More detailed information would help in matching a system for your personal needs, but I can help some. I've heard many of the processors in person numerous times. Currently, I'm working with several of the companies you mention for upcoming events on my web site. Everything boils down to this: quality of installation, personal taste, qualified training and ALL the links in your chain of the system.
The Krell is VERY good and certainly out perform the MC-1 and Meridian in certain regards. I know one dealer quite well and they sell both Meridian and Krell gear with full complement and properly installed in their demo rooms. Their sells are almost 5-1 Krell over the Meridian gear due to the quality. So, I would certainly listen to both of them before making a decision there.
In terms of the Theta Casablanca 2, it's a pretty good match too but still not quite as detailed as the Krell in my opinion. However, you may find it a good match and certainly a processor I would demo as well before buying. The Revels will perform well with any of the three you mention and the Krell very good too.
I've spent some time with the Revel Ultima series speakers and do think they have a lot to offer if you like their sound. The bottom end is quite heavy though and placement can be critical depending upon the room and other factors. Make sure and have the dealer come over with the speakers before buying even if they want paid for their time. It's a major investment and can be good or bad depending upon the room or the other parts of your system.
Also, I would listen to Dynaudio Contour T 2.5 and T 2.1 speakers. They perform quite well and beat just about everything I've heard in their respective price range. It's always good to listen to as many differnt systems as you can for comparison.
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