I have used Komodo 3.5 and then moved up to Komodo 4.x when it was released. It works well in both the Windows and Linux environments. I have not used all the features available but it has helped me through debugging issues much faster.
At the time of the upgrade I think I paid about $150 from personal to Komodo 4.x. From a non-Perl feature standpoint, I think the support for Ruby and the fact that it seems faster then 3.5 help me move along the upgrade path as well as I wanted some of the Pro features that Personal did not have. I have to say from a Perl standpoint there was not significant reason to move other then staying current with releases. I thought for almost two weeks before making the leap.