Yeah, Notes is basically written in the Lotus 123 spreadsheet scripting language :-) Eclipse just made it worse. Obligatory http://www.ihatelotusnotes.com/
The one positive comment I can make is that you did end up with a unified enterprise-wide set of collaboration tools.
Oh there was a new tool I hated before IBM decided to get on the git bandwagon: Rational Team Concert- project management and source control tied into one. Imagine having to start a giant 500 MB Java application to "git checkout". (In fact the project management part was OK, just using it for source control was horrible).
I think these were the worst tools I ever had to use in my whole career. Even after they rewrote the UI with Eclipse later.