Bel Canto v. Conrad Johnson and Pass Labs

I have a Bel Canto EVO 2 which I think I am happy with, but I've been seeing good deals on the used CJ 2500A amp and the Pass Labs X150.5 amp. Would either of these be a step up from the Bel Canto, and if so why? I have the Supratek Chenin pre- amp and Vandesteen 3a speakers with sub.
your best bet is purchasing the new belcanto pre2 preamp. you will be in heaven with the evo on the vandersten"S.