I have had no real problems with it, the service seems to be pretty consistent at least no better or worse then using msn messenger 7.5 etc. In fact I think I prefer this above 7.5 which I didn't at first, there is a bit more flexibility in managing it and the ability to receive offlines has to be a good thing, and something which yahoo, icq etc have been able to do for a long time.
In regards to connecting, I am logged in now and its all ok.