We run both Cpanel and Plesk servers on linux and Plesk servers on Windows. As far as i know Cpanel does not run on windows, correct me if im wrong, we've just never tried it.

I dont agree that Cpanel has more features than Plesk, as far as i can tell the same features exist in both, just at different places in the control panel. In the case that features are missing that you need, there is a great company offering specialized software for plesk, the company is 4PSA www.4psa.com. I highly recommend replacing the plesk built in spamassassin with 4psa spam guardian, and replace the Plesk Application Vault with 4PSA's Integrator. They also make several other must have applications such as clean server (anti-virus), qmail manager, remote backup storage (4PSA Total Backup), as well as a redundant DNS system which allows you to use external DNS servers. The DNS manager imports the plesk zone files directly from your boxes allowing you to run standalone DNS servers. No more having to create new nameservers for each plesk box you bring up.

I also dont agree that end users prefer Cpanel, most of our users who have used both prefer plesk once they have learned where everything is.

Anyway, just my two cents...