Yes, I have, and here are my short-form feelings about Patreon.
1. It does nothing that a PayPal subscription doesn't do, except give you a flashy landing page, and they take an additional 5% out of your money for that landing page as well as the processing fee that PayPal takes out. (Which, hint, PayPal doesn't if you mark your transfer as personal/gift instead of payment.)
2. It's not browsable. If it was browsable, I'd see a lot more utility in it. Kickstarter's model is great, where you can look by categories. Interested in movies or tech gadgets? Here's everything in that category! With Patreon, there's no ability to browse, and to find a page, you have to know the exact search string. "Poems" doesn't get you to pages listed as poetry, "sci-fi" gets you *nothing* when I know Clarkesworld is on there, et cetera, and it only gives you the first few results, not everything that matches that search string. This means that your page is difficult to impossible to find for anyone who generally wants to back the sort of thing you're doing. The only way for people to find you on Patreon is to have your direct link or know your search string; that latter, only if you're one of the lucky ones Patreon decides to return results on. I know zombie_dog has a page for interactive fiction games there, but neither "interactive fiction" nor "games" brings up results for him.
The lack of browsability makes it impossible for people to serendipitously stumble upon your project, as they do on Kickstarter. Not including many results in their searches makes me wonder if they're using the smaller creators who've flocked to the project just as a revenue stream for themselves to boost their Big Names, the ones on the front page with the professional headshots.
I see no benefit in using a service that takes 5% of the money I raise and does nothing in return. Because the utility of a service like Patreon should be the facilitation of those serendipitous connections, but their site is built in a way that makes that impossible.
I know some of you are using it, and I'm curious about your results! I'll also be watching Patreon to see if they make any changes. I hope they do. Just creating a way to find pages would be a huge change. Adopting Kickstarter's model and creating not just browsable categories but a way for users to follow each other and discover new projects of interest? That would kick ass, and that would make me join. But that's not there yet, and it looks like that's the opposite of their plan, based on how the site is structured now.
Being as there's no service yet that really lets me break outside my network for sponsorship, I will be using PayPal's subscription service for my next sponsorable project. I'm going to go take a shower and do some writing now (Nicky let me sleep in til 9:30! Ridiculous pup!), and then I'll do the breakdown on what might be possible. If you have any ideas, if you have any particular content you're interested in, sound off in comments. Obviously sponsorship only works if I'm doing things the sponsors want!