Here's a pretty good code editer alternative to WinRFA, its really good for making quick changes to files without packing and unpacking. You might find it useful - http://code.google.com/p/bga/
I prefer this program for speed editing highly as WinRFA has always been too slow for modification work. Has TONS of features including a quick height map preview. Has a preivew of 3d models when you look at model files. Overall an amazing program that still gets updates on occasion. Absolutely blows every other code editor I have ever used.