Jolida Glass FX TUBE DAC III and III W (Issue with W version) - Opinions?

I purchased a Jolida FX DAC III with the bluetooth feature and liked the sound over USB and optical - could not get the wireless to work properly. So first a word of caution to those considering bluetooth DACs: the Jolida is not a fully-baked option. The first hint that the "W" functionality was not considered carefully by the designers is that the manual makes absolutely no mention of it. The drawings in the manual show the antenna and the "BT" LED in front, but that is it. I was able to get it going by trial and error and turning the unit on and off a few times. Eventually it started broadcasting as a bluetooth device, and I was able to connect using my laptop, a Macbook Air running Maverick. The iPhone was never able to connect. Once connected, the sound running the Jriver player from the Mac was decent, but it lasted only a few seconds before dropouts began. Once I confirmed that happened no matter what player I was running or even from my Windows Surface 3, I gave up on bluetooth and returned the unit to the good people at Music Direct. Listening to music only to be interrupted randomly by a dropout is no fun [note: I was only 12 feet away from the DAC, direct line-of-sight, no obstructions - not that it should mater]. I decided to order a regular unit without bluetooth, because I like the DAC otherwise. Very happy with it, decent sound from a relatively inexpensive DAC that I can later mod with better caps (considering Clarity) and roll tubes (looking for Mullards). It comes with 12AX7 Tung Sol tubes, which sound good enough. I am running Mazda 12AX7s and they sound a tad better (a French military company, not the car outfit) to my ears. So consider this is my brief report on this DAC. Very good sound for the money, and the ability to add tube tone adjustments by rolling.

Has anyone else tried these DAC? I would be interested in your opinions.