I recently got Discourse installed and I have absolutely loved using it!
One thing I noticed is that when you change the title of a Topic there is a delay, the delay is long enough that it appears like it broke when you click the check box after editing the title. I tried to time how long it actually takes, it appears to be 3 seconds from the time you click the check box to submit your edit to the title. The first few times you do this you actually think something is wrong or broken, then you get familiar that this is just how it works.
What I propose is the little spinning graphic that you see when you change pages, it gives a very clear indication that its working and you just need to wait a couple seconds.
EDIT: Odd thing is when I edit my title on these forums here, it happens in less than half a second, so I may need to investigate that.
EDIT2: And Just now I performed more edits, on previously editted topics (on my discourse), and now they are happening just as fast as they do on this site. So maybe it is only the first edit to a topic that is slow. I suspect something is going on, possibly with redis but I am not sure.
EDIT3: and Now all the topics on my site are editable quickly… its almost like Discourse or Redis was in sleep mode, so maybe the first edit got it to wake up, and then all edits after that are fast until Discourse goes back to sleep? I will have to do more testing like trying after a reboot or after a period of inactivity.
(To further clarify I am the only user on my Discourse install, so there are not other users keeping anything acive, we are still in testing and development stage.)