Well after modding the hell out of my A1200, I'm thinking it might be time to sell up and purchase an NG.
Getting all the hardware/software mods to work together was and still is enjoyable, yet frustrating task.
Well you've certainty taken the Classic a lot further than I've ever had the energy to do

The 030 A1200 can of course run 97% of Classic games, an 060 will get you to 99% and PPC will only get you that last 1%....does that give a good perspective on things
If you really want to have RTG then a big boxer is a better bet than going the A1200 to Tower + Mediator (IMHO).
At this point I wouldn't recommend to anybody that they upgrade a Classic to PPC (OS4 Classic want-to-be-users included!), if you really want to try an NG 'Amiga' then maybe have a look at MorphOS or AROS.
