I think very highly of Roger Federer, and would be shocked and very disappointed to learn if he were using steriods. I'd also like to think that, aside from being at the top of their respective sports, he and Tiger have nothing in common. (I think this so called "friendship" between them has been more media-driven than in actuality. Unless Roger is a weasle, lying snake, screwing any and everything he can get his hands on, I don't see what, if anything, they actually have in common at all.)
I was very disappointed in Andre coming out admitting that he had used PEDs; IMHO it greatly diminished his accomplishments in my mind, just as it did with B. Bonds breaking Hank's all-time HR record.
As for Roger...what an athlete! You have to admire tennis players...and cyclists like Lance A., given the amount of physical strength and endurance required to succeed in those sports.