Sorry I'm so late. I just now saw this. I came in here for tuner pedal threads. While we're at it, the onboard tuner on the GT-10 works just fine. It's for the other set up.
To answer your question, in short , I do like this a ton. They both have their digital tone software that they call COSM. Whatever. I like it. Most anything you've heard from me has come from my GT-10. I'm sure some good players have them on YouTube.
I've seen the GT-5, GT-6 and up used locally here both into a HRD and a PA system. The ME-70 at first glance looks good. I'll compare a few differences that I notice as I read the descriptions. Looks like just a totally different set up than the GT-10. Much fewer presets, but how many do you need? (I think it said 36 factory and 36 user) where as the GT-10 has 200/200. And just so you know, I have not used a factory patch in ages.
I'll download the manual and see if there's anything striking. They both have the same loop time. I'm willing to bet that the extra effects I might have in mine are all stuff I could really care less to have. Might have been an amp model thing? I can't remember. I got this two years ago.