I've read a lot of moaning around here, much of it justified of
course.  But just to give you a counter-example, the transition 
went smoothly for me.  I used a Hotmail account for S@H Classic 
in 1999 and I still use that account today, so I entered that, 
downloaded the software and started crunching. I've been very 
impressed with the automated nature of the BOINC client, it is a 
big improvement on my old manual approach of using the CLI.
As for the message boards, I wanted to use a different identity
for that, so I signed-up for another account and was posting 
within 30 seconds.

I made the caches nice and big, so all my machines survived the 
recent server issues.  My total score is 702, with an average
score of 49.  Pity about the site being down at the weekend, but
otherwise it has been superb!