If I were in the market, I'd go with the M1A. Largely, my choice would be based on personal preference. I like wood stocks, I dislike pistol grips, and am intimately familiar with the operating system of the Garand, which has a lot of similarity with the M1A.
Actually, the only reason I don't own an M1A is that it is .308. I don't really want to have to start stockpiling ammunition for yet another rifle caliber! If they made the M1A in .30-06, I'd already have 2.