Don't know if my QRP is an older model, but that knob really sticks out. I've rammed it into my palm when trying to hit the bolt release, and it definitely is a wear point in my rifle case. YMMV, but here are my thoughts:
Con: Knob sticks out, some complain about return to zero, and it isn't as sexy or clean as an LT. Repeated removal & replacement could potentially wear on the ratcheting system. OTOH, I've seen an ARMS that wiggles on the rail, and won't even return to "degree of angle" accuracy.
Pros: Returned to zero pretty nicely the only time I actually took it off after zeroing.
Biggest pro for me: It came attached to an ML2 2x that I acquired for the cost of an inexpensive restaurant dinner. The other guy didn't like it, and all I had to add was the $10 spacer. I don't like the small FOV. Imagine a red dot in a large straw, and you're not too far off. It takes getting used to for closer range, but it worked to keep some plastic milk jugs bouncing at 25 yards. I've not found anything else in that price range, except the $20 ADCO red dot sight on my paintball gun.
Looking forward to seeing pics of that thumbscrew mod.
Edited b/c I my spelling fu was weak.