Rebase key commands drove me nuts forever. I would type something, and all of a sudden it would be jumping around. The keys did not do what I wanted them to do. I would select a line and press a button and the keyboard just did not work right. It was an absolute nightmare learning how to type it. After a while, I got used to it, but with no one to show me and explain, it really was the worst thing in my history of programming. I was trying to rewrite a line, and it took me 7 hours to figure it out without any help. Then one guy comes over and looks and says. Oh, you need to press that button to do that, and if you touch that button, it will do this instead, so do not touch that. Nuts. They could have just made it a normal interface where you clicked an area and then you wrote in that area. It really needs a makeover; even today it still remains unchanged.