Hi Daniel,
I also came from Java environment, used to work with Eclipse from its first versions. This was some 9 years ago. The whole time I waited for Eclipse to come to ABAP world and now finally it happens!
I have to say that also se80 in its latest version is already quite good. But for me to open any number of sources at once in tabs or have only a few opened in different windows (I think you can open only 16 SAP GUI windows) is a BIG difference. (and the "Jump to last edit location"...)
From my practical experience: I develop in Eclipse and no-one knows. It really doesn't matter at all if you use SE80 or Eclipse. (The only thing may be the short descriptions of programs - in se80 you are forced to fill them, in Eclipse they are in Properties - view, so it can happen, that you oversee them).
Locking works normally, it is just automatic in Eclipse, in se80 you have to push the button.
The only reason I can think of is, that the version of SAP BASIS is too old in your target system (which is also our case, I use Eclipse only at customer system).
I would say you install Eclipse und use it, it is easy to install and nobody will notice. (Except maybe the lead programer - by increase of your productivity and happiness).
Have a nice day!