As a long time GT-6 user, I'd say it looks pretty good.
One of my main gripes with the GT-6 is that you never know where you are on any parameter setting and once you turn a knob it moves very quickly away from the setting you had it on.
The Tonelab LE has addressed this problem and it looks like the GT-10 has done so as well.
I note that Boss are touting a more natural tone, which is good. My only other complaint about the GT-6 is that the drive models weren't the best. The effects (reverb, delay, compression etc) were excellent but the amp models were not as good.
I bought a Tonelab LE and while it's amp models are wonderful, I'm not greatly impressed with the effects section.
Perhaps the GT-10 could be the answer for me.