Renly is less regal in the show, but more human, also the gay scenes are a good counter balance to all the gratuitous sex and nudity. His queen is more overtly savvy in the show too, which is good in my opinion.
You're right. I've never complained about too much T&A in HBO shows, but last week was over the top, simply because it was every damn scene and they don't have the time to waste. But...the Renly/Loras scene still counts as sexposition.
Sexposition is a hallmark of HBO shows, but constantly employing it like they do in GoT makes it far less effective than it would be if used sparingly.