This have been said since post #2, but anyways.
I Jailbroke my 3G, just what they said, it depends on what you install on it, I have winterboard and a few other apps, and its kinda laggy some times, and the apps (every app) crash every now and then ,but its still better and faster that any other windows mobile phone i've used.
MINE (with winterboard and who knows what other apps) its slower than what it was before, kinda annoying sometimes, but anyways I can handle it. Im thinking of just modify the files on the phone via SSH , cuase I only use a few different Icons, and a few things, and I never change it and I think I never will, so I may do that and delete winterboard.
The 1st few days I use it, Jailbroken , but CLEAN (without apps at all) i was exactly the same as it was before jailbreaking it, I test it with my Bro's iPhone and both Perform exactly the same