I think overclocking is great for old out of warranty machines, as long as you're careful about it. I have an iBook 700 MHz that I ran at 800 MHz using iCooked, and I overclocked the video card using ATIccelerator.
On my G5, I have overclocked the GeForce 5200 FX using Graphiccelerator to as high as I can take it (any little bit more and games will have artifacting). It did help my FPS scores in games and benchmarks since the bottleneck on my G5 is the poor graphics they put in it.
My friend runs a Beige G3 233 consistently at 300 MHz without problems using the jumper changes.
I have not done any soldering overclocks, but my friend's dad did overclock some 68K motherboards. We got an LC III running as an LC III+, and a Quadra 605 running faster, but another LC III board was unfortunately hosed.
I also had good success with the old clock chips from MC Price Breakers. My 6100/66 ran fine at 84 MHz and my 8100/100 chugged along at 120 MHz without issue. Both were good performance bumps for the machines for very little cash. My 8100 was a real workhorse back in the day. I did everything on that Mac. 8 bit emulators were awesome. (16 bit emulators were too slow though. Those I had to run on the 6500.)
On my G5, I have overclocked the GeForce 5200 FX using Graphiccelerator to as high as I can take it (any little bit more and games will have artifacting). It did help my FPS scores in games and benchmarks since the bottleneck on my G5 is the poor graphics they put in it.
My friend runs a Beige G3 233 consistently at 300 MHz without problems using the jumper changes.
I have not done any soldering overclocks, but my friend's dad did overclock some 68K motherboards. We got an LC III running as an LC III+, and a Quadra 605 running faster, but another LC III board was unfortunately hosed.
I also had good success with the old clock chips from MC Price Breakers. My 6100/66 ran fine at 84 MHz and my 8100/100 chugged along at 120 MHz without issue. Both were good performance bumps for the machines for very little cash. My 8100 was a real workhorse back in the day. I did everything on that Mac. 8 bit emulators were awesome. (16 bit emulators were too slow though. Those I had to run on the 6500.)