I actually have a hard time attempting an answer to this one. I've shot about every grip configuration available for SA reproductions, including the "Thunderer" grip you mention. The problem is, everyone reacts to recoil differently. Some are sensitive wimps (like me), some revel in the "thump" (masochists) and one size doesn't fit all.
I started CAS a loooooong time ago and my first pair of guns were Cimarron Thunderer, 3 1/2 inch barrels, 45 Colt. Full case loads were
a real experience. The thunderer does not allow the gun to "roll" back in the hand. Just comes straight back. THUMP! Snaps the wrist up and away.
I currently have one of my sets of Cap Gun Snubbies with Thunderer style grips on em. Nice to look at, Fun to shoot, not so swell for a Gunfighter. I personally think the Thunderer grip would look "funny" with a 7 1/2 inch barrel (personal thing there).
The only thing I can really say, you pays yer money .... you takes yer chances. Dunno.
Coffinmaker