We plan to do benchmark again with our 4.0 release.
There are many hosting company using cPanel + LiteSpeed hosting thousands of accounts. I am pretty sure everything will work just fine. We will fix any bug discovered.
There is no big difference between 64bit and 32bit LSWS, you will not go wrong with either one.
Update is very easy, just login to the web console and click upgrade after we publish the new release.