Yeah, they are an awesome addition to the game. I recently finished a 24 hour long 7/7 game with core shield generators and the fallen spire campaign, which made for very brutal mid-late game exo waves due to the high number of planets I needed to take. I came very, VERY close to losing several times, and was only able to get my defenses up to acceptable levels by completely eliminating any AI presence within 4-5 jumps of my home system and focusing my defensive efforts along two major areas/routes to my home system. That way, whatever managed to get all the way through was usually whittled down enough for a mk III fortress and mk IV heavy beam cannon to finish off the remaining ships at my doorstep. It wasnt until the end game when I had a fully developed fleet of Spire ships that I was able to prevent them from getting close to my home system again. Exciting stuff!