The two really aren't on the same level. The origin is the budget line of actions and the Impact is a top shelf action. That being said, the origin punches far above it's weight so to speak.
I own a TL3 and played with an Impact. It seems to me that the impact doesn't hang up at the rear of the stroke like the bighorn does, and the impact seems to keep the finish better. The DLC on the bolt on my TL3 is pretty worn down and I haven't even had it a year yet. Both bolts run smooth and lock up tight.
My advise to OP, you probably won't be disappointed with the origin if you go into it knowing that it's $425 cheaper and comes with its own little idiosyncrasies.
My advise to anyone new to customs, Bighorn's offerings are much more versatile than the Impact, but they take some getting used to.
All in all, if you're set in the cartridge you want to shoot and the accuracy difference between a criterion prefit and a shouldered barrel is a hindrance (1/8 - 1/4 MOA difference in my experience) then it's probably worth it to spend the extra on an Impact. Otherwise, Bighorn's offerings are a great option at good prices.