I had no issues with portability and I have the x1 with the q1 and I used it for workouts on the odd occasion (i just wedge it between my body and my track pants with an elastic band, the rubber bands with the q1 keep it from sliding around) If I wanted a bit of an audio treat while im weightlifting at the gym i stack it with the q1, majority of the time though at the gym i use it without but if i can use it for workouts than I'm sure portability is not a huge issue. I have since bought an X3ii but i decided to use the x1 for mainly workouts and the x3ii any other time so i wont wear out the headphone jack on the x3ii since i workout 6 days a week plus the times at night and what not i would be using it.
Majority of the time however i have the q1 plugged into my pc and into an o2 amp with my sennhesier 598's...not because the 598's need an amp but i like to own nice stuff i guess lol. the q1 sounds great btw...very crystal clear. Whether or not i hear a difference with the q1 vs o2 amping the headphones is hard to tell, i would have to do a side by side comparison with the 598's and takstar pro 80s.
if i were to compare the x1 +q1 to the x3ii...i would still rank the x3ii higher in sound quality by a small margin...so if you are concerned about portability for the best sound quality i would just get the x3ii. If i were to reverse time when i purchased the x1 and q1 i would have just bought the x3ii, but now its nice to have a cheaper dedicated player just for the gym.
sorry, i realize i may have not directly answered your question but I'm hoping my experience can help you somewhat.