Classic Integrated Question: Krell or Classe?

a krell is not twice as good as a classe

I owned the Classe CAP-100. It is very good. I liked it better than the raw and unrefined Krell KAV-300i. No experience with 400XI so cannot comment.
Personally I would go with Classe CAP-150.

Can't speak for Classe but I have owned the Krell Digital Vanguard with my Vandys 2CE's and that combo was amazing. Very Very Dynamic and Revealing! Had great experience with Krell customer support too. 

the original post asked if a krell integrated is worth twice the price of a comparable classe

that is an easy one, already answered hell no

depends as usual on what a buyer values... krells are extremely overbuilt, classe’s are less so - sq differential is much more of a mixed bag

krell over the years have made some wonderful pieces (particularly their ksa class a series) but also some truly bad sounding true dogs (esp. when they tried to do home theater type amps)

classe used be one of the sweetest sounding solid state brands, always beautifully voiced, imminently listenable for long stretches... classe as a company has also changed it focus in more recent years - both companies have changed ownership at least once since their heydays

so research and care need to be exercised in either case, make sure you get one that is truly worth owning

Thanks for your responses. Given the info here, and what I have read regarding these two pieces, I’m leaning towards the Classe for its described sweeter, more musical sound character. I did have a krell kav-300i once, but it was bright, harsh and bass was overbearing—in my system anyway. 
Question on xlr. Are all xlr connections louder than rca?