IDE?? I don't need no stinkin IDE! Notepad is your friend!
BTW, I use MS J++ on my Win NT 4.0 machine and compile the code to run on an HPUX webserver with JRE 1.1.8. J++ is fine for compiling code and is actually quite fast compared to JBuilder on the same machine. WHen I say fast I mean moving and opening windows, scrolling (the scroll wheel actually works, go figure! Something I wish JBUilder would implement), and compiling. The speed of the code is another matter and one which I am not qualified (or intelligent enough

) to answer.
The things you lose are Java 2 improvements and bug fixes. Threading is a little flawed in 1.1.8 and you don't have the collections classes. But since our web portal is going away to be replaced by a J2EE framework in a couple months, my company isn't going to upgrade until then. THen we are getting JBuilder 6 so that we can do that J2EE stuff.
I've found that Kawa Pro is a good alternative but I don't think Allaire markets it anymore.