FWIW, I'm only planning to switch to carb because it'd be too expensive and too much of a PITA to go from CFI to EFI than it would be to go from CFI to carb, and because CFI is just all around garbage for performance ... and perhaps not even all that great for reliability, either (although it seems to work great on my truck for that much, at least). If I had the time, money, parts, and a whole shop to go drop in a whole motor and all the wiring bits to an '86+ 5.0 in my '84, I'd be all over it, but alas I'm limited to weekend driveway projects until I can afford to buy a place with an enclosed garage ... which is years and years away from now, probably.
As stated, it depends on how much time, money, and effort you're willing and able to put into the conversion, the parts used, and the tuning of the finished product.
Personally, I think you'd be money ahead and saving yourself a lot of hassle just to stick with EFI and upgrade that, as opposed to switching to carb. You think you've got problems now with trying to make your EFI system work, wait 'till you create a whole new series of variables by switching to a carb setup, essentially starting from scratch, and trying to get that whole deal to work together right ... and without the aid of the EEC-IV system (basic as it may be) to help you in any way to diagnose any drivability issues.
