I don't have an SR on my HQ sitdown and haven't missed it. I do think it does take some practice but if you are used to a domestic the learning curve is so small. I too have a brain block to a long arm. I think a lot of it is what you have trained your brain to do. If you have only pieced on a domestic then FMQ might be easier on a long arm, but if you FMQ on a domestic (moving the paper) then moving to a sitdown has very little change.
My dealer was amazed at the fact that I sat down at the HQ S16 and just started FMQ -- he left me to my devices to play with it pretty quickly and I walked out the door with it.