I use this with my HD6XX Sennheisers from Massdrop. The sound quality is impeccable and very clean - no coloration and basically as good as my RME ADI 2 DAC ($1,100 device in the same category of devices as this one).
This new version should perform identically as my Version 1, the only difference being is this Version 2 has an output impedance of ~10 ohms. Going by that metric, the safest bet is to always use a headphone with a devices with an output impedance of 1/10th headphone you're using.
So basically the cuttoff limit for this Version 2, is using headphones with no less than 100ohms.
The consequences of doing so - means that your frequency response of your device will change, and make your headphone sound different. And that's something most people don't like to have.
Since yours are 250 ohm headphones, this device would suit you well and good. But any future headphones you may have that are less than 100 ohms, might have their sound signature change when you listen to it on this device, versus a device that has ~1 ohm output impedance.
The Version 1 of this device had that 1 ohm impedence, but for whatever reason it was causing failures for some folks (mines' still running fine though thankfully). So they made this Version 2 more reliable it seems, and upgraded the Bluetooth capabilities as well on their way.