This is a opinionated decision from all aspects. The threshold (which I have ridden) is 200 dollars for a deck alone w/ brake. The Revention is 250 (about) which includes: deck, headset, brake. Now, if you are looking from a money standpoint, youd think the Reventon is better, but a good FSA is about 30 bucks, so buy yourself a Threshold and an FSA and thats around 230ish, which is a better bargain.
Now from a riding aspect, i have ridden the Threshold a few times and it feels amazing, 4.5x20, feels great, but if you like longer decks the Hep sig 4.5x20.6 feels great also. The Reventon only comes in 4.25x19.5 and 4.65x20.5 (not including sig models.) So personally i like the feel of a 4.5 with more foot room so the Threshold is better in my opinion.
Now for the actual riding info (got sidetracked up there) The Threshold is amazing for grinds, the extra grind space that it gives you is incredible. I have never ridden a Reventon but from what I have heard they are a little on the heavier side (all opinion), and I have seen plenty crack, but im sure Thresholds will sooner or later also. So its really your opinion, they both come in just about the same colors but the Reventon has: Green, black, red, and orange. The threshold has: Black, white, green, purple, silver, and raw.
Now thats about all i can give you on the decks from my opinion. I love the threshold and proceeded to buy one for myself just a couple days ago.
Hope you have an easy time figuring your choice out! (sorry for typing more than needed to be said, I personally enjoy more information than not enough.)
Todd.