I was looking in Stereophile and the Krell was listed as $11,000 which would definitely put it closer to the 5A's
I do think the 3A Sigs are one of the great buys in all of audio. I think, from looking at the review only, that the Krell is a little pricey for what you get but that's just me.
You need to listen for yourself and decide. So much of this is personal preference. I do think when looking at $11,000, your options are wide open.
The 3A Sig is a little fussy about placement but rewards you for your time. The 5A is the best, most put together sounding speaker I have heard to date and will be my next purchase this summer.
Also, vandersteen does make the "Quattro" loudspeaker at $6500 that is reported to be a slight improvement over the 3A Sigs. It has built in subs.