I used the term "minimal" in my original post because compared to their other trail shoe offerings, the Pure Grit is relatively minimal in design (flat, simple outsole, sockless liner, minimal overlays) but I don't think Brooks claims this shoe to be a "minimalist" shoe. They do throw around the words "natural" and "anatomical" like it's going out of style however, so yeah, definitely proceed with caution and be an informed runner and know what works for you and what doesn't- not what Brooks claims works for you.
I have a low arch, not completely collapsed but close- my left arch is slightly lower than the right. Despite having a low arch, running in neutral shoes has proven to work best for me and feels best underfoot. The Grits are definitely not as neutral as the 110's, there is some midsole build up in the arch possibly for slight overpronators, but nothing to shake a stick at. I definitely wouldn't call the Pure Grits a stability trainer, but if you're typically running in non cushioned zero drop "barefoot" style shoes, then yes, this is going to be overkill for you. The hefty amount of cushioning is the biggest divergence from the MT110. The thing with the MT101 that I didn't like so much was that it was, yes, neutral, but allowed for too much lateral foot movement due to the floppy mesh upper, it also had a relatively severe drop (9mm) which only seemed to increase as you compressed the forefoot down over time.
Found this article this evening, worth a look for anyone directly comparing the two...