Gotta consider the scenario. If I'm drafting for a keeper league, I probably go with Beltran, one year league, I go with Giles. If I have an existing team, I'd look at the rest of my team and see if I think it can contend this year, if so I'd get/keep Giles, if I wasn't going to contend and had my choice of the two, I'd probably go with the younger Beltran. Also gotta consider the format, Giles K/BB ratio makes him more valuable than Beltran in points leagues. In roto, depending on the other players you have, Beltran gives you the opportunity to finish strong in the steals category.