Any RME ADI-2 DAC FS owners here?

The RME ADI-2 is an excellent AKM449X implementation, and for that sound it can certainly compete with some more expensive DACs. You may find it a little cold, analytical, and dry, but that really depends on your own subjective calibration point. Others won't perceive it that way, and there are other DACs that are even more so in that direction on the spectrum.

Whether or not the headphone output itself is powerful enough to bring out the best of your headphones will depend on the headphones you're using, but it is quite capable.

The biggest downside is the relatively complex UI and customization options. Most consumer DACs and headphone amplifiers have a few choices and a volume knob. The ADI-2 has a whole lot of settings and a bit of a complex interface; you could easily (mis)configure something and not know it or have a hard time undoing it.

@vineman55
You wrote that you had it for a while. Why didn’t you keep it and what did you replace it whith?

@nekoaudio 
I’m not afraid of all the options. On the contrary, they are one of the reason I’m curious of the DAC.
But maybe it’s not a DAC for me being a ”tube guy”. My amp, my headphone amp, my other DAC and my RIAA uses tubes. But with tubes both in the DAC and in the headphone amp makes the sound a little veiled. At least with my gear.

I've had my RME for about nine month's and I find the sound transparent and dynamic. Picked it over the Chord Qutest. I use the short delay slow and tweaked the top end w/the 5 Band Parametric EQ. Also to make your life easier go Audio Science forum on page 28 of RME ADI-2 thread is a four part video produced by RME on how to use your DAC. Excellent step by step instructions. 

@simna I wouldn't recommend the ADI-2 DAC if you want the sound of tubes. Unless you find you're getting enough of that with your other tube gear, and want to lighten it up a bit.

@simna   I still have mine...