Quality per $ my vote is the latter Gen ETR or MT, that is if you haven't ruled out a used Cronus G2.
I have the Ares BTR G3 2.5-15x50 and I'm pretty well convinced it's as well built as my Cronus G2's and superior to these scopes in this price range category or even more expensive - the Bushnell's, Vortex's, Vector, and Meopta I own now or have owned in the past.
I kept trying various scope brands out and so far I wasn't as happy with these and it was always that there were notable downsides. Basically I found Athlon had the best balance of positive attributes and by far had the best turret feel, most distinct, the least lash, and lines on the turret lining up well with the line on the housing.
If you wanted to save more money I've found the Helos G2 6-24x56 a really good scope as far as bang for the buck but it doesn't have the IQ that the higher end Athlons have. It's been good enough that I kept it on my expensive 22rf.