I was searching this exact question last year. I heard a lot of the amps you mention including the McIntosh 6900, the Krell, the BAT, the Levinson. I've heard the Manley Stingray, Jeff Rowland Concentra, and the Gryphon 2100. I finally settled on the MF Tri-Vista, because I thought it would be the best at driving my JM Lab Alto Utopias. I think all of these amps are superb. I've heard the McIntosh with Kef speakers--top of the line. I heard the BAT with Thiel gear, the Krell with B&W 800 Nautilus, and the Manley and Gryphon with Dynaudio Confidence C1s, C4s and Avant-Guard Unos. I thought the 2300 dollar Manleys outperformed the 7300 dollar Gryphons on most recordings but there were a couple that sounded a bit distorted. The BATs were impressive and had a deep soundstage. But I didn't like the Thiel speakers much. I actually quite liked the McIntosh and Krells. Macs were good all-around amps. The Krells worked quite well with the B&W configuration. They were a bit dry but with my music--electroacoustic--they were highly appropriate. Since I listen to other music besides EA, and since I feel that tubes are superior to solid state, I finally chose the compromise solution of having a tubed pre-stage and solid state power. I'm glad I settled for the hybrid solution. That said, I also heard Pathos gear--both the Logos and the TT, which are both hybrid and I didn't like either. I thought the BAT was superior to both. The MF has given me some well-documented reliability problems but I can't complain at all with the sonics. I hardly ever turn the volume past 9 o'clock. It's a powerful unit and drives the Altos with ease. If i have one regret though it would be not being able to hear these speakers with Jadis amps. I would very much at some point like to hear them with the Orchestra Reference SEs, which probably aren't powerful enough to drive the Altos, but I'd like to try anyway, just for curiosity. Perhaps some day I will replace the MF with Jadis pre and power combo since this is a match that intrigues me, but Jadis gear is expensive and hard to get a hold of used at a decent price, so I may not have an opportunity unless I save up for many years. Otherwise, I'd say that the Tri-Vista and the KW in all likelihood (haven't heard it) are probably the top integrateds--mainly because they are engineered to do so much and have so much power. The two box solution allows for huge transformers to be used. I think the idea of making an integrated in the manner of separate pre and power configurations but combining the circuitry in one box and putting the space hogging power supplies in another is one of the most novel solutions for producing high quality integrated amps. I would like to try the Pathos Classic at some point, and I've yet to have access to a YBA Passion Integre. My general view though is that solid state can't come close to tubes. I've heard some very detailed solid state equipment that has impressed me, but I think tubes breathe more life into the music. I was simply aghast at how well the Manley outdid the Gryphon on that score. Less is often much, much more. Hope this helps.
