Then there were 2

I'm not familiar with Rogue but if it were my money, I go with ARC. The Resale value is better and I know it has great sound quality.   ARC has a sound quality reputation that has spanned decades - they aren't going to ship second hand sound.

Rogue makes good stuff.  I had the M-180 monoblocks for a long time and they were great.  I own a couple of ARC pieces, but haven't heard the amp you're looking at.  If buying blind, I'd lean towards the ARC.  I would expect it to be just a bit more refined and as mentioned, it's going to have better resale value.

of the two, I would choose ARC

however, I much prefer the Quicksilver Mono 120's, and think this:

Pair of Quicksilver's, with KT150's is under $5,000. 

ARC is $10,000.

I would wait forever for the Quicksilvers, and use something else in the meantime. However long you wait, it is but a speck of time.

Two mono amps can be moved by one person, more placement flexibility, different cable lengths, ....

You could buy a used pair of mono blocks now, use them, sell them when the Quicksilver finally materializes.