Both players will be 24-years-old in 2007 with Russ Martin having the edge in MLB and minor league experience.
And in 57 September ABs, Iannetta has drawn 9 BBs for a .382 OBP versus Martin's .356 OBP in a considerably more reliable AB sample.
In Martin's favor is he has improved his extra-base power by hitting 10 HRs, his 2nd highest professional total, and 24 doubles which match his high, and three triples which is a professional high. heck, it doubles the number of career triples he had previously.
He is also a solid play for 8+ SB in 2007. I'd expect that to diminish in a couple years as he is only successful about 2/3 of the time now. More major league wear won't allow enough attmepts to crack double-digits if his rate decreases at all.
The main difference between the two players next draft will be one of perception. Russ Martin coming off such laudatory articles like "Martin Has The Attributes of a Great Catcher" by ESPN's Jerry Crasnick will have a premium attached to him.
Chris Iannetta will fly under the radar and is likely to provide the same production sans SB as Martin for half the price - if not a quarter of it.