I've been trying to find out for awhile and haven't found out much, since the GT-10 was just released 2+ months ago.

So is there anything the GT-8 has that the GT-10 doesn't, or vice versa? Obviously, the GT-10 costs 50$ more, so it must have something else, or they just want more money.
it's newer? other than that I don't know anything else eather other than the easy tone controls and stuff
one looks like a toy and has a looper inside. The other is more than you'll need even though its older.

Saying the GT10 is out GT8s will be selling for proper bargins.

A few guys over there have them, some are saying it sounds loads better than the GT-8 (less fizz, better dynamic response) and is a lot easier to tweak, others don't seem very impressed.

A lot of people are complaining that the LEDs for the effects blocks are blindingly bright and the big screen could make it more vulnerable to be broken.

I'd wait for a while to see what people are thinking of the GT-10 and try one out for yourself.
Got on the bus with me daysavaaaa