Ayre Codex - to keep or not to keep

I'm using a balanced headphone and the RCA out to my single-ended amp in DAC mode.  Here is my concern, when I do A/B comparison using headphones in balanced and unbalance modes, there is a night and day difference in the sound quality. In balanced mode, the music is much more resolving at all volumes (especially higher volumes), with better imaging and sound staging across the highs and lows. Initially, I thought the major difference was just the increase in volume but now, I don't believe that's the case. In general, Ayre's equipment really seem to be designed to be used in balanced systems. Can anybody confirm that in DAC mode, the XLR balanced outs sound noticeably better than the unbalanced RCA outs like with the headphone outs?  The Codex still sounds very good via the RCAs but I'm wondering if there are other DACs in the market, in the same price range, that sounds better in a single-ended system.   With that said, I have few different options, one I can move away from a single-end amp design and get an amp with balanced circuitry (would like to get the AX-5 Twenty for it's out of my budget and AX-7e is not powerful enough for my speakers) or I can look into a getting a different DAC that works better in a single-ended system.  Let me know what you guys think. Thx
greeni-I am having similar selector issues with my Codex too. My audio dealer recommended powering down the unit by pulling out the power plug while on and then powering up normally 15 minutes later. It worked the first time, and the second, and the third.....but I don't want to keep doing this every two weeks or so. 

So now i am thinking of getting another DAC, with similar sound qualities. 
Mine, so far, is running like a champ. No issues so far. Just great sound. Especially in balanced mode.
Mine's running like a champ too. I wish it was easy to switch between USB and Toslink, but since it's not, I just keep it on the latter and use a Toslink switch to change sources. Otherwise, it just keeps on chugging. 
I'm surprised an Ayre rep has not attempted a response to the above noted problems.  Ayre has quite exceptional customer service and is known in my experience to be responsive to customer questions and issues.