I'll echo what has been mentioned previously, I too don't understand the disproportionate foot pocket size on both the Accel and F2, in XS and Small, the foots pockets are huge which is strange given a) one would assume someone looking into XS sized fins has small feet and b) both are tauted as travel fins so one would assume general purpose warm water with thin boots. I've owned both and sold both. I could never get a good fit out of the F2s regardless of boot type, I even changed out the spring and tried other lengths. I managed to get a "reasonable" fit out of the Accels using Mares bungee straps but still wasn't great.
I found both of them wanting in moderate current and woeful in a reasonable current. If you have narrow feet or wear light boots you might run into fitting issues, goes without saying try before you buy.
The Mares Avanit Quattro + are almost the same weight as the F2s but IMO a much better fin, of course their legnth may make packing in a carry on difficult. I recently bought some Apeks RK3 fins, small and surprisingly light, comfortable and relatively powerful given their small blade surface, they are my new favorite travel fin.