I'm not a big fan of the flippers on Flash (sluggish, clunky, weak, etc.). I was originally thinking of just rebuilding them with new parts, but I've heard its really the design that sucks, and a rebuild would help but they would still suck. I've played a couple other games from that generation, and they seem to all be like that. I recently read a thread (http://www.tomshardware.com/forum/59658-13-flash-generation-flipper-upgrade-awesome) where some guy upgraded the flipper assemblies to the next generation Firepower style assemblies (http://www.pinballlife.com/index.php?p=product&id=711).
What does the pinside community think? Rebuild or upgrade? Is there anything to the upgrade beyond removing the old assembly and making space to mount the new one? How about voltage for the new coils?