corporate solutions run on Red Hat not Ubuntu. Thoughts...?

[Damien Hull]

I'm looking into different enterprise email groupware solutions. The ones that do calendaring and file sharing. The truly open source software solutions run on anything. There are a few that are Red Hat and Suse only. 

Here's what I'm looking at. 

1. http://www.zimbra.com/ - I'm using this on Ubuntu

2. http://www.scalix.com/ - Red Hat and Suse

3. open xchange - community addition runs on Ubuntu 
http://www.open-xchange.com/wiki/index.php?title=Community_Edition_Installer


QUESTIONS

How do Ubuntu server administrators feel about the lack of Ubuntu support?

Should I switch my servers to Red Hat? I haven't do this because it costs $$$.