I have both
I have the Ufly/QC15 setup, which i wear at work driving aluminum skinned passenger haulers. It works great, but I find in my O-360, FP Sens prop with vetterman that when the battery gets weak, i.e. the green light is flashing, the noise canceling will kick off when i say go over a runway light, or have some other loud different noise excursion. I can still hear but you can tell the noise canceling is struggling. so i put in a new battery and good to go again.
I also have a bose X, the wife usually wears it but I have used it a few times as well.
the QC15 is much lighter and to me far more comfortable over longer time periods. however, I have a bit of trouble getting the mic close enough to my mouth and stay there all the time, i have to help it periodically. The bose x is a better performer, never cuts out, and the mic length is more favorable.
the QC setup has an advantage in that you can use the headphones for other things, like riding in the back of said passenger hauling device. Customer service from uflyMike is outstanding.
I only bought the bose x because the wife needed a headset and i got a good deal on a used one. after the way bose treated the uflymike people, i wouldn't give them my business ever again...
my 2 cents worth...
Stump