No comparison, whatsoever. Oris by a mile, every day of the week and ten times on Sunday.
But then again, it depends on what you're after. If you want a watch that 19yo sorority girls and aspiring rappers at the bar happy hour might recognize, obviously go with TAG. If you want something that's actually a quality timepiece and worth the MSRP, then it's not even a question between the two.
I purchased an Oris Aquis in a Tokyo GM shop new for roughly $950. I consider this the greatest steal of a watch purchase I've ever made. The bracelet is gorgeous. The ceramic bezel shines magically. No, it's not on par with my Omega PO or 126610ln, but for $950??? It's my go-to "bar" watch on the weekend when I think I might be staggering by the end of the night. Sure, my female cousins look at it and go, "WHAT THE F*** IS AN ORIS???" But I didn't purchase the Aquis for them.
I once purchased a TAG Aquaracer from a GM shop for $1700. I looked it over for about five minutes. I put it away. I came back an hour later and played with it for another five minutes. Then I promptly shipped it back for a refund. S**tty ceramic, horribly s**tty bracelet with a cheap clasp and push pins (on a $2600 watch??), and on top of all of that the movement was busted.
TAG makes some flashy watches and that might've appealed to me twenty years ago, but if I'm spending my hard-earned money then I want my money's worth. I've said it before, for $750 I'd happily buy the new AR with the two-tone bezel, especially one in blue, to be my travel beater. But there's now way in hell that watch is worth four-figures. Ever.