Well, personally, I think you win either way because BOTH of those vapes, the Extreme and the PD are both great vapes.

Aw hell, get them both. That way, you'll have a whip vape, a bag vape and a direct draw vape which you can rotate depending upon your needs and mood.
A lot of people do this and end up using the PD as their daily workhorse because it's so good at conserving weed, and then whipping out the Extreme for party use (bags) or for when you want super-thick bong rips (whip).