I have been using Cartalyst's packages for about 9-10 months now. Like you I started at Entrust/Confide and I switched to Sentry, at the time was a wip @ version 3

From my experience, if you're looking for support/quality and constant updated Cartalyst is worth it for sure.

I can't speak for Entrust/Confide's support but I've yet to wait longer than a couple hours before getting some sort of reply and help.

Sentinel always being updated and the roadmap (what they're adding to extend that package) is also WELL worth the money.

You can always just sign up, try it out and see what its like.

Something I can't seem to find on their website, do I lose the license to use the Cartalyst products if I stop my subscription? Or do I just lose the access to the repositories, so I can't get updates anymore?

I would assume I just lose the repo access and updates but I can't tell from their terms and conditions.

Correct, you simply loose access to the repositories. no more updates, new packages, or support.

https://medium.com/@Cartalyst/boss-sheet-8019c5e07246