If you're worried about a tune voiding your warranty then I would suggest staying away from the PMAS. Only because if a tune voids it, then I'm sure putting a different MAF will void it as well. I understand they use that MAF so that you don't need a tune. But it still would be frowned upon.
There are lots of intakes on the market that do not require a tune and will give you solid gains in HP, TQ, and throttle response. I went with Airaid. But Corsa, Injen, and a few others make quality intakes. You really can't go wrong either way but I think Airaid is the best one out there. Steeda also makes a no-tune required intake. And the good thing about it is that you can remove the insert at a later time if you did decide to get a tune.