Sorry to sound like a snob, but what kind of a developer are you if you do not grasp the basics of how a computer works?
It's OK, but hopefully you don't mind if I defend myself
I originally made this thread more hoping that somebody would pick up on the "I moved everything from an older iMac" piece and say "previous experience on the forums has been that moving from XXXXX installations to YYYYY installations can cause performance issues for ______ and _____ reasons."
I'm a proud owner of a CS degree, and have taken the classic "operating systems" class where we went through CPU delegation algorithms, drew state diagrams, talked about (here it is!) paging and memory management, etc. So if you had asked me "what is paging" I could have given you a pretty good explanation. BUT, I didn't know what "page-in" vs "page-out" was, or which was hitting memory or which was hitting the HDD. So, I googled it
Finally, while I started out with C++ and did C++/Java through college, after college I've been mainly programming with the web languages (PHP and some Node.js for fun) and I've met quite a few other developers (and we are writing real, honest to god OO code, design patterns and all!) who DON'T have the background that you and I might, and wouldn't know what paging was. So while I'd argue that a super well rounded developer would probably understand how a computer worked, I don't think it's an absolute pre-req for being a developer (or even a good developer!).
Now that I hopefully have defended myself (sorry, but the internet is serious business!), thanks again for all of the replies everybody has given. It sounds like more RAM in the box might not be a bad first step.
The one "catch" to all of this is that it's actually a work computer, and while 60 bucks isn't a lot to my boss, I still hate asking. But I think it'lll be worth it.
Of course, I'd still love to hear other details or opinions!
Oh, and the two largest memory hogs seem to be Firefox and PHPStorm. PHPStorm I'll give a pass (~700 MB) because I have a fairly substantial code base open and I really love auto complete, but Firefox (also ~700 vs Chromes ~100-150 MB) is ridiculous.
Oh, and as a final point, I'll say that I still maintain that Lion feels significantly buggier and slower then Snow Leopard ever did. I don't like the new features (well, besides the App store but that was out in 10.6). I am generally not happy with it.