I used to have an X350--a generally fine sounding amp, especially in mids & highs, but bass was a little opaque (using Aerial 10ts at first, later Wilson WP-6s).
Switched to Edge NL12 (now with Kharma 3.2CRMs) & would never go back to Pass (or anything else). I don't even crave tubes any more. The Edge has great, great clear bass, oodles of detail with out being harsh or grainy, deep soundstage, completely un-fatiguing while sounding live & real. Also, the amp gets only slightly warm at all times, a major benefit IMHO, unlike the X350 that would heat up the room (sometimes unbearably). I would definitely try an Edge amp, I think it's my amp for good.
(Absolute sound was right about Edge.)