I was going to root my stock Froyo (JP6) and install the Voodoo lag fix this weekend, but I appear to have stumbled on a solution - on my phone anyway - that almost completely eliminates any lag, but for the usual 5 second pause when installing an app that I've seen on all android phones (and my iPod Touch - FWIW).
It's simple:
1. Use ADW Launcher instead of launcher Pro or TouchWiz.
2. Use SlideIt instead of Swype. (I suppose you could use the stock Samsung keyboard, too - haven't tried it.)
That's it. I've been using this for 36 hours now and it's like I have a different phone.
Can anyone else who has not installed a lag fix on their Froyo JP6 (if there is any such person) test and confirm this?
Ta.