Andy, if the Bachs sound relatively undynamic with your CJ amp, then there's a good possibility that the Beethovens will be a similar situation. If you're stuck on the CJ, then I'd do everything I could to audition the Beethovens with this amplifier. Your room size is very similar to mine, and I also have my speakers firing along the long wall, so there should be no problem there. FWIW, I haven't found anything near their price range thats been as musically satisfying to me, but like any high-end component, they will not match well with everything. Hopefully a CJ/Vienna owner out there will chime in.
Matt
Matt