There are a lot of posts on this forum about this debate. They always boil down to one thing, what each user prefers.
The Outback is the older of the two boats, so it's hull design is a generation behind the Revolution. It's very stable, but yes, the Revolution is a little bit faster. Neither of the boats is unstable.
If you have any chance to test them out, I would do that. We can each tell you our opinions of which one is best, but you'll have users that prefer completely opposite boats for exactly the same reasons.
ex: "The Outback is the better fishing platform" "No. The Revolution is the better fishing platform"
Both are great boats, my vote would be for the Revolution, but I don't fish at all, so I probably use a different set of criteria to evaluate a boat. I'm also a few inches shorter than you, and you may find that one boat has a little bit more room than the other.
If you like the Outback, but want more speed, you could always opt for the Turbo Fins, if price is the main determining factor, than buy the Revo. However, I agree with what was already posted. For the couple of hundred bucks difference, buy the boat you want. It's not worth buying the wrong boat for that much money. Very few Hobie Mirage drive boat owners regret spending the money after they have the right boat.
Of course it will come down to the ride....... I just need to get in them and test them out. I need an all around yak and by reading through the forums, either boat could work.