Auto Task Killer just reconfigures the OS to kill idle tasks quicker. Without it, my G1 running 2.1 crawls after an hour of use (same with my ZT-180 Android Tablet running 2.1). With it, my G1/ZT-180 run fairly fast. I never "use" it, I just configure it and forget about it.
I have not put ATK on my G2 yet as everyone says not to use it on Froyo. I don't understand why not to though. I may try it if my G2 starts slowing down. Hopefully that will never happen.
It doesn't take tons of apps to slow it down, just a few that insist on remaining in memory for no reason (which is most apps with widgets, even if you are not using the widget)
Cell: HTC One Dev.Edition - Stock - Solavei
Home: SideKick 4G - GloriousOverdose v5
- configured for SPI/GV (WiFi phone only)
CarPC: Epic4G - CM10 - configured for SIP/GV with FREE 500MB/mo service through FreedomPop.
Tablet: AdventVega - VegaBean RC2