Any mod that can be completely reversed is ok by me (I'm eventually going to replace that q950 fan). The only problem is that it's very hard to remember how everything was in the first place (esp. in compact macs)!

Guys, don't mess with your 128Ks if it's stock.. you can always pick up another compact mac for cheap to play with if that's what you really want to do. There's not much difference across the compact mac range in terms of hardware anyway.