Loaiza was never good before 2003, he added a cutter in '03 and had a hot first half. If you guys remember correctly, he really began to fade in the second half, especially September. This was coming; he's a one-year wonder.
Beltre, on the other hand, was rushed to the big leagues sooner than he was ready. He's always had the talent to be a big-time player. Don't forget, he's only 25. There are some damn good prospects out there that are 25, not hitting 36 homers with a .900 OPS by mid-August. I think Beltre is going to be a damn good 3B for a long time.