Personally, I dont like the idea of having a completer etc on the normal scripts editor. Sure, it takes time to learn how to do things. But then, after you've learnt it, even if not all of it, you get the satisfaction that you have just made something yourself.
Granted, I'm not the best of scripters, but I know enough to keep myself going, and most of that is stuff I've learnt from the help file. You just have to build up your knowledge and not just jump in the deep end and fall at the first hurdle.
I know this isnt entirely relevant, but I feel that created codes/scripts with a completer, (imo) is kinda cheating. Sure if somebody only wants to make a one-off script for their mIRC, then it would be helpful, but, i dont think it is entirely needed. If they want to do something simple, the help file should have all the info they need in it. If they want something complicated, they should go on a dedicated site for mIRC scripts, and look/request what they want.
Thats my thoughts anyway