This isn't too ideal until you hit 3056 Haste. At that point, Haste is near worthless until you get to the next plateau. 3056 Haste is pretty important though (and very easy to get)
---------- Post added 2012-11-19 at 05:24 PM ----------
@OP: Unless you get a very lucky string of Pyros and get 3-5 on each side of an Alter Time, you won't see 30+ too often. I once got 71k though when I got EVERY SINGLE Pyroblast crit
(Roughly 9-12 crits)
Also, if you have PoM, you shouldn't ever Combust w/o it because both cooldowns are 1.5m (90s) (You ARE using the glyph, right?). While this will change once you get your 4P T14, if I use PoM on a fight, I still plan to use PoM with every Combust.