Hey, look, people choose what rules they want to use. Not a lot of people use planetstrike, etc, because frankly the rules are unbalanced and nonsensical. But some people do, and if my buddy, really, really wanted to I could be convinced to do so for a laugh.
Forgeworld? I'm more inclined to pick by the unit whether it's "ok" or no.
Tournaments are just the same thing, except it's a group larger than two people voting on whether it's OK or not.
All the supplements so far, seem relatively balanced, at least the 2 pages or so of rules meant for "normal" 40k.