Often when I join it's 762 is full and hslan is empty...
The other day, 762 was full and there were three people on hslan when I joined, thinking "well, at least I can get some practice". Within minutes, other people started to join and the server was full soon. Lesson for the day: there might be a full server's worth of people (or more!) lurking in the waitscreen, waiting for a slot to open or a ranked server to fill up sufficiently so that they could join.