If you can't afford to overlap the two bikes, just google "cam chain tensioner" on the GT and you'll find plenty of reasons not to buy one if that is your tendency.
I replaced the left-side cam chain tensioner on my '03 RT, as recommended by an expert mechanic. So RT's, at least the older ones, have a cam chain tensioner issue. Personally, I thought BMW NA should have stepped up to the plate and offered to do that under a campaign. No such luck, but it wasn't that hard to do.