I think B.Giles is a serviceable OF for 2K5. I'm not saying he should be the centerpiece of you OF, but real solid anyway.
I drafted him as my RF in one league so far this year. I took him at 8:12 in a 6x6, H2H, 12 team league. He was my 3rd OF taken and the 9th RF taken overall. Vladimir Guererro; Bobby Abreu; Gary Sheffield; Magglio Ordonez; Miguel Cabrera; Ichiro Suzuki; J.D. Drew; and Jeromy Burnitz were all RFs that went before him. Sammy Sosa; Trot Nixon; Larry Walker; Austin Kearns; Moises Alou have gone after him.
I think he'll have solid numbers across the board. Nothing crazy, but still solid. I think he, like most other SD hitters, will adjust their game to PetCo Park. I think his numbers will take a slight upward bump. I owned him last year on a roto team and can't say that he actually hurt me.
Yes, age can be a concern, but that is the Only concern there is with him.
.292 BA, 27Hrs, 96RBI, 98R, 9SB, .889 OPS