I have my jailbroken 4S, it's nice.
But with my wife's 5, I play with it and I can see myself liking it. I don't use much tweaks, just simple ones.
SBSettings
BiteSMS - just for QuickReply
Switchy
Five Icon Dock - I can live without it.
Five Icon Column - really no need since I the screen holds 5 rows.
Granted the tweaks are cool, but if Apple added QuickReply I'd most likely upgrade.