Did the new frame have more clearance, like enough for 40's. THe Grade has some nice geo numbers but not being able to run 40's would be a deal breaker for me.
It depends on what "40"s you are talking about.
I run Clement LAS on Arch rims....which measure out to around 39mm.
I tired a 40 MSO on the Grail rim and it fit...but was too tight for me ( and I'd never use a tire that big)