I wondered the same thing on a smaller scale, and did a couple tests. While others will say that they aren't scientific etc., the results speak for themselves. But, if the doubters want to provide another test and instructions (that won't take much time), I will be happy to run them on my PC running RedHat 7.0 and my Ultra 10 running Solaris 8 64 bit, or I can even run them on a Netra A200 (UltraSpacr II 500 Mhz/512 RAM) or E4500 (6 cpu's and 6 Gb of RAM).

http://www.1le.net/~1le/unix/unix_ws_tests.html

I just finished setting up an Oracle cluster with 2 Sun 420R's around 2 D1000 arrays using Veritas VCS & HA Oracle. It seems to work very well, but it was a lot of work!
Good luck.