Running it on a 3GS.
Things I like about it:
• iMessage - free to other iOS5 devices and the group messaging is cool
• Find my Friends - useful for when meeting a group of people and can see how far away they are
• Changes to home screen notifications
• Wireless sync
Things I don't like/bugs:
• Having a few issues with Calendar
• I think it may only be a 3GS thing but in reminders I don't have the option to location remind me
Also having some problems with Mac OS X 10.7.2 .. Half my iChat contacts were deleted :/
