I may do a comparison test in the future but I don't have anything except gameplay with the MTR-16: https://www.youtube.com/user/ucanhascheeseburger/videos?view_as=subscriber
The vast majority of my shots are close range (under 30 meters) but even for longer range shots across the field, I am easily hitting people from 50-60m away no problem.
Cutting nubs is very easy, you just take a sharp blade such as an X-ACTO knife for cutting cardboard boxes and cut straight downward on the front of the nub, being careful not to cut at an angle or make a messy cut. If you don't do this mod, your bucking won't be able to apply pressure evenly across the patch because the barrel gets in the way.
I haven't tried the TNT bucking with the brass nub, but I would imagine the brass nub would perform very well just about any flat or R Hop shaped bucking. Due to the concave shape of the nub, it will give the bucking contact patch more of a curved Maple Leaf-esque shape while a flat nub will apply a... well... flat contact shape over the BB. And due to the limited space where the nub can fit through in the hop up chamber, a slightly bigger nub won't make an insane amount of difference.
I've noticed that the most important factors are: 1) the nub must be very stiff and stable 2) the hop arm should be stable and not moving from side to side 3) the hop chamber should also be centered in the outer barrel, and 4) the contact patch must come down perfectly evenly over the barrel window after everything is assembled. #1 can mean anything from the brass SixG nub to the TNT flat nub (due to the length of the TNT nub it will require slightly more modification than others) to the Maple Leaf Omega Tensioner concave nub or even a Modify flat nub. #2 and #3 can be helped with a CNC hop chamber/arm combination lke the Laylax MWS hop chamber, or a small roll of teflon tape. #4 comes with a lot of patience and time.
If you find that the Modify tan bucking wears down too often for your liking (it is an old design after all), I would highly recommend the Maple Leaf MR Hop 60 degree (if you're not using a lot of full auto) or the TNT TR Hop 50 or 60 degree, paired with a solid nub of your choice (assuming 350 FPS w/0.2g BBs). There will be a slight break in period of 300-500 rounds, but your bucking will last many thousands of shots easily.