The man has had an amazingly up-and-down career in the eyes of the public for someone who has been pretty consistently decent for the majority of it, save for an absurd spring training at age 19 and a perhaps PCL-fueled (but perhaps wrist finally healed to match his maturing body) .380/.426/.546 at 21/22. In between, he's been compared to Sean Burroughs, Adrian Gonzalez (both back when it was an insult, and now, perhaps, as a compliment), Mark Grace, Rafael Palmeiro (minus EITHER performance enhancer attached to his name, if you know what I mean) and even Nick Johnson.
To me, I see Loney as much more of a power threat RIGHT NOW then Burroughs ever was. It's not even projection. Ignoring today's game, almost every reasonable at-bat he's had (i.e., not at-bats in meaningless late innings against lefty specialists, which, miraculously, the Dodgers have managed to get Loney at least four that I was watching), he's put a charge into the ball, and hit it somewhere deep and hard. The man just puts good swings on everything -- I had a preseason bet with my dad that he'd hit .400 in Vegas after watching him in spring training, a bet I'll happily lose at .380 -- and now he's starting to elevate those linedrives.
(The New, Improved) Adrian Gonzalez and Mark Grace are fine comparisons, because they play defense as well or better than Loney (though neither has the first-round pick as a pitcher arm going for them). These guy will hit a lot of doubles along with mid-20s HRs. A very solid player, assuming he last 7 to 10 years (Grace) at such consistent productive levels, and a good player if that only lasts a few (I'll guess and say it's so for Gonzalez, who I love, but I don't see him matching Gracie's career stats.
I guess Nick Johnson just fits into the discussion as a first baseman with mostly doubles power who has chronic wrist injuries that keep him on the DL. The actual players themselves seem quite distinct, but there is some eerie overlap.
Finally, you look at the ceiling for Loney -- who Logan White dreams of li'l Jimmy becoming: Rafael Palmeiro. The guy who the Cubs so famously traded, saying "he doesn't have National League power for a first baseman." And, even when Raffy's 'roided arms were launching balls deep into the night at the Ballpark at Arlington or Camden Yards, the swing was too soft, flat and smooth to be from a real 40 HR guy.
Do I think Loney is Palmeiro? Hell no. First of all, I would be surprised if Loney ever actually hits 40 bombs in a year. Consistently sitting in the low 30s wouldn't surprise me at all though. Further, what made Palmeiro a legend, before, you know, he made HIMSELF a legend, was his consistency and longevity. If James wants that kind of longevity, he'll have to talk to Raffy about the performance enhancer Palmeiro pitched legally back in the day. Kidding aside, I just don't think there's any reason to BET Loney's going to last long.