My playgroup has done the "neutral all planes shared deck" thing; in fact, we've never played Planeschase the way it was intended, but I think a better method is to have everyone choose a set of planes (say, 5-10) and shuffle those together to create the shared plane deck, rather than using all of them.
If you use the full set, certain deck types are just left in the cold; for example, there are far more planes that support aggro strategies than pillow fort (which makes sense, because there are more aggro decks), but it just creates a situation where certain players are favored before the game even starts.