I don't have a clue as to why the thread is closed but I saw it quoted somewhere else and thought I'd reply.
I am 1/2 of the CMRA team who 1st won the overall mini endurance championship w/ an EX250 back in 2007. I have raced the old gen and the new gen and many other bikes and have set a track record in a CMRA ESS sprint race on an EX250 old gen. I built our championship winning bike w/ 08 EX250 forks/wheels to try and keep up w/ the new gens. The new gens are just a little better. Mainly the forks being thicker tubes and the 17" rims. They still chatter when pushed but at a faster speed so you can carry more corner speed. Oh yea, lighter too. But frames are super thin walled compared to the old gen.
I own Road & Track and I helped w/ the suspension on the CBR so I got to see it nekkid.
The CBR is lighter stock and gets down to about 40# lighter than the EX in race trim. The forks are the pretty much the same as the EX and the shock too. What makes it stand out as a better platform is the frame. It has a shorter wheelbase and looked like a steeper rake (but I didn't measure). It looked more like a racebike to me than the EX ever could. The downside will most likely be maintenance issues and $$$ to repair.
Oh, as far as CMRA not being a competitive org, there have been more US and world champs from this small club than anywhere in the world. It is pretty serious racing.
BTW - I built the suspension for almost all of the top EX250 teams .
Sorry to ramble