Granted the current seti for BOINC-stats isn't very accurate since just got credit for a long backlog, but we've been outcrunched by BBR since August. And according to the latest RAC they're crunching 2x as much as the TeAm...
Since it's highly likely all users running seti@home would have run "classic" if BOINC hadn't been an option, Anandtech would example crunch 300 wu/day more in "classic", but at the same time BBR would have crunched 600 wu/day more in "classic". So IMO having seti for BOINC actually helps the "classic" Anandtech-team.
As for BOINC not working, CPDN for BOINC have AFAIK not had any problems, except v4.03 didn't work on NT4 & win9x, but the newest v4.04 even work on these older OS.
Seti@home for BOINC have had many hardware-problems, but AFAIK after the latest database-changes there haven't been any problems, and no problem getting enough work. As for the core client, haven't had any problems since beta-v2-something, and the core client is not even marked as "beta" any longer.
The seti-application have also run without any problems.
As for why use BOINC, even the latest seti-application is slower than "classic", the BOINC-version is more effective since normally only crunches the same wu 3 times, while "classic" has now an average of 7.51 result/wu and increasing so it's probably nearer to 15 results/wu now.
This really means that even with the slower seti-client under BOINC can use 50% of crunching-power in other projects like CPDN and LHC and only crunch 50% of the time seti@home, but still do more seti-science than if running "classic"...