Not a fan of taking Lackey. I'd rather take the best pitcher or maybe even Jacob Lombard, who is supposed to be better than his brother (a top ten overall prospect) was at the same stage.
Georgia Tech catchers have been overrated for years. Also, I know it's a super small sample, but if you're worthy of the #3 pick in the draft, you probably don't go 3 for 25 in the Cape Cod League. You can disregard it, but really most college players' real value comes out in the CCBL. Lackey struck out 6 of 26 PA. For comparison, Cholowsky played there a full year younger and struck out 7 times in 65 PA.
Georgia Tech is a hitters' paradise. Numbers are inflated big time, and it's only really behind Tennesse for big-time schools (a major reason I didn't like Billy Amick). You can't ignore this by hoping it's untrue or thinking this doesn't apply to a hitter you like or want. I would pass on Vahn Lackey and take Lombard or a top pitcher if both Cholowsky and Emerson are gone.
And by the way, TB is flush in catching prospects, namely Nathan Flewelling, who is very likely better than Lackey. They're flush in shortstop prospects, too, though play them elsewhere, who cares. The biggest thing the Twins can hope for is that the Rays take the best pitcher and leave Roch or Grady for the Twins.