Right on man, there are definitely issues with the rule set. And though I personally draw enjoyment from mission writing and rules tweaking I can completely understand why people find that frustrating and 100% agree that you shouldn't HAVE to do so after spending so much for the rules. I don't think that that makes this the worst edition yet though.
I've been playing since the tail end of fourth and I never had a great grasp on 4th's rules, but of the three that I did play regularly I'd have to say that 5th was the one I liked the least, mainly because I found the rules of that edition to really encourage particular play styles across all the codexes (parking lots, anyone?) while the most recent one at least lets you play more to your particular style and, in a non competitive format, have a chance at a fun and challenging game (please note I did not say balanced). That's not to say that some of the current codexes don't encourage particular lists over other, but at least that's more exclusive to the codex instead of the edition as a whole.