ok, so it would need to be filled a couple times an a vacation then. Do you bring your own or are resorts able to do that?
I have been to some more off the beaten path dive areas. Usually if they have nitrox, they have some sort of O2. You can decant their O2 if you bring a whip and some fillings.
I have been faced with 20-30 dives with O2 for just 5-10. You can make up for that by flushing the loop more often with a sling bottle of nitrox, but it cuts down on the fun factor.
The sorb is clutch, but you can usually check that as baggage or ship it ahead easier than tanks etc.
If you are going somewhere warm/easy a good number of people stretch their sorb due to high water temp and low work levels.
-matt