rookervik, what systems are you having performance issues with? There’s no reason you shouldn’t have perfect performance on Pi2 with a 1080p overlay. There’s a couple of things you might want to check:
Is your Pi overclocked? I have mine set to the Pi2 setting.
Are you running at an unusual resolution?
Does your retroarch.cfg have video_threaded set to false? This was changed recently in the RetroPie-Setup script to be false by default – however, it was found it negatively affected performance if you were using shaders or overlays. If it’s false, try setting it to true and see if that helps.
Otherwise, feel free to PM me and I’ll see what else I can do to sort you out.