I love it in Mavericks. Works with a chat window perfectly. I'm even able to enter text and exchange chats while the window is untucked and then I simply move my mouse away and it "tucks" back out of sight again except a tiny edge.
Looking forward to tabs as an option in the future although I hope it doesn't become mandatory for all the windows. For example, I don't need a tab for that chat window.
My only real complaint is the Swipe feature requires too fast of a swipe for me. I'd prefer the swipe to be able to be slower -- or better yet allow me to adjust it myself to my own preference.
Seems stable and handles moving to other Spaces just fine. The developer currently has it pop out a little each time as a reminder it's there, but I think we'll be able to remove that feature with an upcoming update if we want and I'll like that. Also, labels will take care of that issue for some as well.
This has a lot of potential to be a huge time saver for those who don't want some unstable bloatware added to their system, but want to organize windows and reduce clutter.
I only took off one star for the too-fast-swipe business.