You can also define a local directory as apt source folder: https://askubuntu.com/questions/170348/how-to-create-a-local-apt-repository
In my opinion the world isn’t that black and white. For example in my experience let’s compare eclipse (FOSS) Netbeans (I think it was FOSS too) and Intellij. Eclipse and Netbeans were both great IDE’s in the early days. The open plugin architecture of eclipse made Netbeans a de-facto dead project. But the extremely pluggable architecture of eclipse became the biggest disadvantage, e.g there were plugins which were incompatible together and it happened really fast that you broke your IDE. Besides the many legacy interfaces which were still present because of backwards compatibility made it really difficult for a new plugin developer to know which interface to choose for which functionalities. Then there were Jetbrains with their new (proprietary) IDE Intellij, which came long after eclipse, and increased there Market in a very short time, with a very stable piece of software and a clean and intuitive UI.
I was a long time user and defender of eclipse, but in the last 2 years I worked with Intellij and never looked back.
Does it support visuals like ProjectM?