Well if you want to see one, that can be arranged next time we are both in LCY! Prepare to be underwhelmed though!
As far as I know, the RJX flight deck is essentially the same as the RJ, only difference being the EICAS/FADEC (for the new engines). Sad that they couldn't have upgraded it to a "real" EFIS steup.
I have seen the RJX flying from Woodford a few times, it appears to have a lot of performance compared to the 146. The test crew were certainly flinging it about the sky with great enthusiasm.
I guess we'll soon see how it REALLY goes...