Finally got reaction fire figured out. Took some trial and error but I got there.
Alright, couple of things. Something sticking their head out and shooting will not trigger reaction fire. Something moving around past 'x' range for your current weapon will not trigger reaction fire. If something pops up in range of multiple reaction fires, they ALL fire... at once. Wasted shots... though I'm not sure there is such a thing as overkill against Mutons or Crysallids.
Additionally, change your Assaults to their pistols instead of the shotties if you reaction fire them. They will take 2% shots with the shotty if given the opportunity, you might as well use something useful. Same with early snipers when they're moving. The Pistols will let you move and reaction fire with the team, and it costs nothing to switch back to the sniper at the beginning of the next round if something wandered into killable range for you.
I'm still torn on snipers. Btw, snipers are quite powerful. There's a choice, either you can shoot/reaction after a short move, or you can hit basically anything on the map. I've got a pair of snipers that are part of the 'main' team, one of each. I still am undecided which is better. Nice open forest-y map, and Longshot rules the roost. Urban annoyances? Move and plink, move and plink.
There were some odd design decisions in this game regarding aiming, as well. What appears to be an impossible shot gets 80% hit rates if you're flanked to their cover, no matter what should also be cover between point A and B. Example, I flanked a sectoid with my heavy (double shot rules all) and ended up having to shoot over the back of an open 18 wheeler's trailer. Since I'd flanked the sectoid's position he was 'open' to me, but that truck really should have given him at least partial cover... and didn't, simply because he wasn't directly next to it. In realtime games I get why you might fudge some of that stuff, but I'd have expected the unreal engine to have collision detection already involved. *shrugs*
If there's one thing that will annoy a lot of folks in this game it's the interface and level manipulation. You're constantly battling the 'ceilings' on buildings/UFOs, trying to find the right position for the cursor indoors, and generally the cursor gets really chaotic near map edges when tossing grenades or the rockets (free fire is not kind sometimes here), and sometimes even just trying to move. When you're trying to position yourself next to a door on the wall (a big deal to stay 'quiet') the wall immediately fades out so you can't see where the wall ends and the door begins... so you can see inside the building. Considering it's a 3/4 view game and you can rotate the view in the 90 degree quarters, I'm not entirely sure why they felt this constant 'see through' was necessary, or the granular heights. It was a nice idea, but it's not workin' so great.
Let's see, what else. Medics. Make sure you always have a medic. Maybe two. They're 'support' but that 3 usage medkit is just impressively powerful... particularly if you ever want your assault guys to survive missions.
Heavies have missiles but really their power is in the LMG + 2 shots/turn if they don't move. Snap a scope on top of that and let 'em rip. I've got a heavy with dual grenades as well but you don't really use them unless you're caught with your pants down... you don't get any of the gear in an explosion, so really the power is in the main gun. Just keep a decent pistol on 'em, they run outta ammo quick, usually, and there are times you just need to get that kill shot.
Assault class... oh, assault class. Alright, if you like your assault class (like I do) for starters you really need to get "New Guy" in the officer's training lounge to auto-squabbie the rooks. Then churn your hiring/firing till you get enough of them. Don't really need to fire them as far as I can tell, but when you've got 10 snipers it's probably overkill. Unless you're on ironman if your snipers are going down you're restarting a mission anyway. Close with the team using pistol for a bit of range work (laser pistols are cheap and are useful enough). Also, hand these guys your tasers. They're already close so they might as well do the zapping... shame you can't use 'em when you 'charge' through the sprint. I haven't tried 'em with spiderman armor yet (skeletal) but watching them climb in second story windows should be pretty dang funny.
The tech tree is deep, and even on normal you're eventually going to run into fundage problems. The limiter in this game is your cash flow, really, not necessarily time. Trying to build your base out will empty your coffers, particularly since you need to dig the holes in the first place. If you don't get a steam 'room' in the top 2 levels just restart the game, power's far too expensive otherwise. Also, I haven't found a single thing I can build yet that I can sell on the black market. No more turning yourself into a manufactury to supplement your lousy income. On the bright side, most squad gear insta-builds.
Engineer and Scientist recruitment is done in an amusing way, but it's not well explained. # of scientists affect research speed, easy enough. # of engineers actually will limit what you can build, at all, as well as lowering the costs of production. So, no going direct to superweapon, you won't have the # of engineers you need to get there. You also can't hire engineers or scientists. There's two ways to get them. One is at the end of the month different regions will provide different numbers of eng/sci dependign on how many satellites you put over their head (btw, fill a region and you get the 'bonus'). The other way to get them is as rewards for the abduction missions (my bad earlier, I'd said they were terror missions and they're not).
Those Abduction missions usually come in sets of three, and the more panic'd the target, the higher the difficulty of defending the abduction run... which is where you usually want to go to reduce panic, so it's a bit of a catch-22. The other two areas will increase in panic, it's just par for the course... which leads me to a small strategy... don't put up all your satellites. Leave a gap or two (until you're nearly filled in) so you can satellite a panic'ing country and get it to calm down again. So, you slowly grow your eng/sci cap and there's basically nothing you can do to get more except for wait for the end of the month or do specific abduction defenses. Terror missions are a whole 'nother story.
Fail a terror mission (so far they're only coming one a time) and you lose that country permanently. Poof, we're out, bye bye. Your first one will let you know if you've got enough heavies with you when the crysallids come after you. I recommend two minimum for any terror mission, unless your snipers are godly... which they most likely won't be yet. Two and Two is better. Fill in the gaps with a medic and an assault dude. There's a nice little bit they added to Terror Missions now though... you can evac the idiots... errr... civilians. Just walk someone up next to them and they run directly to the ship and are 'saved'. No more being forced to leave one sniper WAAAAAY in the back in case some sectoid slipped the net. They're still the centerpiece of brutal though.
Finally, difficulty. Normal vs. Classic is all I can directly speak to but there's a few key points to be aware of. Difficulty significantly affects how quickly places will panic. Miss an abduction in Normal and oh well, I'll get back to you. When you skip one in Classic it makes a huge difference, and you're always forced to skip two. I don't know the best way to work around that yet, satellites and the controls are very expensive to build so you can't just setup the defense grid for the world in the first two months. The other thing is that the computer is about AIWar level 5/6 in brains on Normal and about a 7.6 in Classic, at least as far as it's canniness can be considered.
