SR generals are, for the most part, a stopgap until you can get the SSR and UR generals that you really want. The only SR general that I've seen other players use much at endgame is Naoe Kagetsuna, and that's usually an SR Naoe Kagetsuna with another inherited SR Naoe Kagetsuna for huge regen. One other SR general worth mentioning is Usami Sadamitsu, for her skill to reduce the defense of all opposing units by 11%.
Mostly you want to focus early on on SR generals who have a useful skill to inherit, so that you can still get some use out of them for a while after you've got SSR generals. Healing skills remain useful for a long time, and I also like the +15% attack and defense skills.