Hi Shannon,
I've had both. The Aadland caps are brick shithouses. However, the finish is more like a "stippled" finish and I'm not wild about it. The TT's, as supplied on my ZP5s are nice, they just aren't as beefy as the Aadlands. They have the smooth finish that I like. The TTs allow you to directly adjust the objective, whereas with the Aadlands, you have to remove the cap to adjust the objective.
at the end of the day, I like both caps. To do over, price being equal, I'd probably go with Aadlands. That's not a knock on the TTs though.