I have the ERC-3. Great player. IMO it would take multiples of the MSRP ($500) to best it. That said, I can also speak to the downside of the unit. I’ve also talked to Lonnie Vaughn a few times and got his take on my observation(s). First, if you haven’t seen the video of him explaining the player, you ought to:
https://www.youtube.com/watch?v=AASMX6zpOogTo your specific point about RCA and XLR, XLR is preferable. What is not known, however, is whether or not the unit is *truly* balanced through and through. It is thought not to be. No bigigy there, just keep it in mind. The RCA also sounds great, but as I might have expected, has a little bit less gain than the XLR out. I’m guessing some where between 3 and 6 db less.
On the negative side of the player, it (motor spinning disk) is *very* noisy when compared to other players. Guessing a 2 db increase and it is audible within a foot or so of the unit. There is much negativity by some in other forums about that. However, from the listening position which would likely be many more feet away, it is not audible (to my ears).
On the positive side, regarding the noisy motor, the rationale by Emotiva is the unit uses a significantly better class laser than most players and therefor can and opted to spin the disk about 1200 RPMs, many times (3 or 4) faster than most players. As a result, the error correction in the ERC-3 is purported to be very good (and I can vouch that it is). So, if you have scratched or less than optimal disks, this player should be able to read them with no problem.
Great player and a great value when all things are considered.
Edit: I have no experience with the Music Hall C-DAC15.3. At face value though, from what I can glean from
http://musichallaudio.com/c-dac15-3/ and the fact it may be a bit *more* expensive, I would go with the Emotiva :)