can this interface comfortably drive these headphones. Im getting mixed opinions.
I really would not want to have to get a seperate amp. Thanks for anyone who has tried to respond.
one more mixed information:
the headphone output of the ur22 mk2 is not very powerfull. to my ears the sound is very nice and very clean and for me is it loud enough for nearly all of the time, but…. for mixing and mastering it might be o.k. for you and your ears and how loud you like/ need it to be.
for you and youre headphone with 62 ohms and powerfull 105db spl/v? it can be o.k. it can work, but maybe its no loud enough for you. so you have to test it for yourself, or get another brand with a more powerfull headphone amp.
but you really have to test it out for yourself. sorry.
for headphones with 100ohms and more, and/ or less the 90db spl/v you´ll need another interface, or better a good and powerfull external headphone amp.
so for me and my personal point of view: i only have headphones with 32ohms and their sensitivity are open 96db ( for mixing, mastering, and fun listening) and three closed headphones, one with 105db (mixing/recording/tracking) and two with 115db spl/v (for tracking, or when i need more loudness) 32ohnms 115db is twice as loud as the one with 32ohms 105db. thats enough for me in my home setup and the position of my headphone gainknob on my ur22 mk2 is about a 1/2 to 2/3 most of the time, sometimes even less. but with tracking or some low level recordings, i have to crank up the volume to max. for checking the noisefloor or something like that. sometimes i´ve wished for a bit more power and headroom, and there are some other people really struggling with this issue of this interface. so there is no right answer for anyone. mixed opinions!
so, for my needs it´s absolut o.k., but it really depends on how loud you want/ need it. otherwise, even with the volume at max. to me the sound ist pretty good. and exept for the tracking stage with dirct monitoring, you have many tools in any daw to make everything louder!
and in my case, i don´t use active studio monitors like most people do, i use an amp with passiv speakers, so i could use the headphone-amp of my amplifier for a lot more power if needed.
long story, but if you haven´t bought a interface yet, this maybe would help a little. or confuse you even more. (like me, when i was trying to find the “right” answers to my thoughts and questions!)
i know there are some other good interfaces, having more powerfull headphone amps build in. and some others with even an less powerfull amp, or sounding bad at high volumes.
maybe its better for the own trusted feeling, to have more headroom. this psychological things might sounding kind of silly, but… we are human. arn´t we? 
on the other hand, many folks like or love this device, some people think its o.k., othe folks hating it. it can work. mixed opinions! 
I’m going to buy a schiit magni 3 amp so problem will be solved. The interface is great otherwise.
Thank you so much for very good reply.