What problems have you had with HEOS? I only have a few systems out there but the customers love them and I haven't had any problems yet (been over a year since I sold the 1st one now).

The biggest negative I can say about HEOS at this moment, is they seem to have abandoned the CI market of it. You can now buy direct on amazon.com for dealer cost (and sometimes a few $ below dealer cost). This was really a kick in the balls to all of us dealers. Yes we could try and sell it for whatever we want, good luck with that.
The SONOS people are having a field day with this of course. After bitching about the margins so much on SONOS and praising HEOS for given us a little more - LOL, now SONOS at least 'has' margin in it. HEOS giveth & HEOS taketh away.
Also, trying to ask questions to the representatives at HEOS results in crickets. Indeed, they haven't answered a thread in their dedicated forum at IP, since last year. They hadn't even checked in since last year but I noticed recently 1 did check in real quick last month - but no replies to any of the threads.

[edit]: I went and looked on amazon.com real quick. It appears Denon has gone back up on a lot of the prices for the HEOS units (although some are still at cost).