Hello, no (unexpected) problems on my end (neko.im with somewhere between 300 and 400 concurrent users); there were a couple of servers which didn't have TLS properly configured or enabled - I don't think this is the place to name and shame, but at least two of them had 'secure' in the name. Some fixed it by the end of the day (although, not the two aforementioned). Once Google gets around to enabling encryption on gmail.com and Google Apps (or they disconnect from the network), I expect I'll be enforcing encryption permanently.
Sincerely, Nulani.