The KAV integrateds are known to be cold...something that is different than the older Krell sound that many people like. The 400 integrated supposedly is much better, different.
Having purchased the Naim Nait 5i for a friend and listened to it critically with some friends, the Nait 5i was a clear winner, even compared with an integrated that cost almost 2X more than the Naim. The older Naim sound is different, you might either love it or hate it. The newer Naim sound is different. With the music you like, I say NAIM NAIT 5i.
Having purchased the Naim Nait 5i for a friend and listened to it critically with some friends, the Nait 5i was a clear winner, even compared with an integrated that cost almost 2X more than the Naim. The older Naim sound is different, you might either love it or hate it. The newer Naim sound is different. With the music you like, I say NAIM NAIT 5i.