I tried the demo for at least one of the SBK games recently (may have been SBK2009) and didn't like it at all. IIRC, they had the brakes reversed such that the rear brake stopped you really fast.
GP-Bikes is the most pure bike sim I've tried to date, made by people who at least have something of a clue when it comes to vehicle dynamics, but it's very much an unfinished project with only a few bikes and 2 tracks. I think it's also based on the ISI engine, which tells you something about the quality of the other bike games on the market that I would actually like an ISI-based game.
GP Bikes is good but unfortunately the creator has decided to start over again, apparently because not enough people bought it and development stopped.
It feels a heck of a lot faster if you're actually driving it, but the problem is actually that unlike rally games, RBR is as close to simulator as the sport has ever got so it is generally well under 100mph
Yeah, the East-West section in Australia is so awesome when you get the right speed
I wonder if there will ever be any decent rally game which is even half as good as RBR some day