Let's be clear.....
There's a
HUGE difference between FOTRS (Fall of the Rising Sun) and Fotrs "Ultimate". Suitednate, you've asked about FOTRS, so I'm assuming that's exactly the mod you're referring to.
Actually there's little comparison between the two. FOTRS was the basic model for "Ultimate", but it's been left well behind in shear number of ship models; how they look and perform; and general game play. FOTRS needed more than just a cosmetic "face lift", and the overhaul is what's in "Ultimate".
I can't speak for FOTRS...….but I will for "Ultimate". It should perform much better than FOTRS. If not, there's an "active team" that's working on it to make it better, where few other mods can say they can do the same.