1 TB of dropbox space costs $ 9.99 per month ( that is $ 0.005 for 500MB, $ 0.2 for 20 GB).
. No limits of collaborator count (you as a space owner choose). No dependancy of the DAW brand. And much cheaper than Pro Tools cloud.
I like many of the new features that PT 12.5 collaboration but they are of no use (in 95% of the cases) when I have to collaborate with musicians who have Logic, Cubase or nothing (except that they are extraordinaire musicians).
If I am lucky, maybe one or two guys working on a same song are having PT 12.5, but as soon as take another guy to the project who has not, we all have to quit PT12.5 collaboration mode and come back to dropbox sharing - just because PT collaboration is so restricted, with no third party cloud or sharing support.