The following are personal opinions.
Since I am on vacation, I got to spend a lot of time on the Foundation and I think I have come to a conclusion sooner than expected. I am a tweaker when it comes to audio. I love to tweak listen and go through that cycle until I reach a point that matches my personal taste. I got used to Audyssey Mult EQ XT32 Pro that allows you to tweak to your dreams and this unit does not offer me that yet (hope it does someday). The best the foundation offers me when it comes to tweaking is trim levels, input assignment to memory and what range to tweak for EQ. Unfortunately for me, those are not enough knobs. If I want to do mid-range compensation or HF roll-off, I don't have a choice. Is mid-range compensation or HF roll-off important, probably not. So it boils down to personal taste in tweaking. I can tell you this. When it comes to 2-channel stereo and absolute best in sound quality for mulit-channel audio, the Foundation is unbeatable in this price range. I have tried a dedicated 2-ch stereo setup with a flagship Sony XA5400ES, through a Rogue Audio Athena preamp and a Rogue Audio Medusa amp. That combo is like the ultimate in 2-channel I have experienced and the Foundation is in par. I have not done an A/B side by side so I cringe to comment further. I know good sound and all I can tell is that this Krell Foundation is a spectacular sounding unit. I wish Krell some day will make a deal with Audyssey to get it on board. While the Krell shines in almost every other aspect, room correction is wanting, UI is wanting and so is the user manual. Not for the most, but for me.