Suggestions for New/Used amp under $3500


My System : Von Schweikert Unifield 2 speakers. Preamp outputs from a Denon 3311ci receiver. Room size is small (12x 15 x 8) but opens up into dining and kitchen. Possibility of moving into a larger space so headroom is desirable.

Planning to order a couple of amps and keep the one i like. Ability to drive center channel also would be a nice (but not mandatory). New or used does not matter.

Wondering if i can do better than Channel Islands Audio d200 mk2 monoblock pair.

Based on reviews and recommendations i have considered the following options:
- Emotivas
- Odyssey
- parasound
- butler audio
roxito
There is a Pass Labs X250.5 that would blow away anything you are considering.
I have a Butler TDB-5150 that replaced a Rotel RMB1095. Pre and Pro are Emotiva USP-1 and UMC-1. Speakers are Salk HT1TL's. The Butler brought my system to an entirely new level. Soundstage depth, air around instruments, instrument decay all improved to jaw dropping levels. Frankly I'm surprised that this amp does not get more press. Huge upgrade versus the Rotel.
Based on online reviews, posts and personal suggestions, the following is my assessment of audio quality (not considering other factors like price, weight, size, heat, power consumption etc)

Emotiva < Odyssey < Butler < ci audio

Not sure where parasound fits in that ordering.

The Pass Labs X250.5 may be much better but does not appear to be within budget... even in the used market.