Plesk has been losing money like crazy and just got bought out. We tried it. Didn't like it.
Search our support forums for the number of times plesk is used (and cursed) which is another reason we stayed away from it.
Ensim is no picknick, and needs to be installed on a brand new install, it cannot be laid on an existing server.
Haven't tried cpanel recently but we did like Ensim better a year or so ago.
