I've never hated the Sheffield's. In the room they sound pretty damn good (I'm thinking the time I played a JSX with the matching JSX cab). Never mic'd them, but from this clip it sound liek they can hold their own. My only complaint was that they could not handle massive amounts of low end like V30s can, but they still kickass in a bind.
From this clip I prefer the the Sheffield, but the sounds of the v30s sounds nothing like the results that I get with my V30's, which I absolutely love.