I find reprisals/scrap to be extremely punishing when I play maps without chokepoints and with high cap low hp high death ships, while i find reprisals to be extremely rewarding when i play chokepoint maps and low cap high hp low death ships.
Comparison between my 2 ongoing games, both vs lv8.6 (everything+random)x2.
- maze a easy map, 60 planets with no nomads, translocator bonus starship, time ~4h30, I own 13 planets including one AI homeworld planet, almost ready to assault second AI homeworld and win game, I'm almost always on the offensive
- simple map, 60 planets+nomads, raptor bonus ship, time ~5h30, I own 5 planets, I haven't been able to find either AI homeworlds yet, I'm almost always on the defensive
Basically I find reprisals+scrap to multiply the advantages of chokepoint maps and low cap high HP bonus ships.