I have always used VIM for developing. The main reason being its high configurability, you can do pretty much anything with it. But it does take some time to get it setup right.
Also it does not create any weird code or files that you have no control over.
While it suites me perfectly there are some features I do miss. So I took a look at Eclipse.
It has some very interesting features and from what I have seen so far it seems like you have good control over what it does to your program.
I will be trying it out for a while and see if it is worth doing the switch. So the next version of Mediocre will probably look a bit different, with some new folders that Eclipse uses.
It will probably take a while to get comfortable with it so wish me good luck. :)