other than major speed improvement on FP1, there's quite a few tweak as well.
FP1 almost open everything instantly, e.g.
instantly open contact with 21 field details
instantly open messaging, messages, gallery, notes and the left soft key is improved a bit
does not need to restart for changing Network settings from Dual mode -> UMTS -> GSM (nice, it's getting "smarter"😉
would love to see this in the next firmware update. it would make e61i even better