My biggest complaint with the Ubuntu packages is they install their own copy of the entire stack. Apache, Tomcat, OpenLDAP, then entire thing! This is obnoxious at best!
Mostly because I want to install Zimbra on a shared host.
Secondly because it strikes me as silly. Ubuntu spends all this time trying to get these packages well tested, well working, and STANDARDIZED to a supportable time schedule (Dapper, etc), and an ISV just ignores it.
What is so wrong with just using the built in packages?