I have been told the same on this forum and in quite a few reviews. On my CM16 carbine I had to replace the nub because it was massively overhopping out of the box, with the hop off. A replacement of the nub and resetting all the placement of the barrel and such fixed the issue. It now hops about even with the hop off. I wouldn't exactly call that legendary.
Then when I got the T4-18 I saw much better accuracy straight away compared to the CM16 (shooting at paper at 10m). But then I got out into the field and applied hop and once I had it right I found the rounds were being pulled about 12 moa to the right, it was well away from the zero I had set. The vertical pull I was expecting, the horizontal I wasn't. At range I had 3 person widths of spread at least, I had some rounds over hopping and some under hopping so it was really inconsistent. I knew it might take some time to bed in and I have now put about 3000 rounds through it so I am expecting the hop to behave now, but it doesn't seem to be any better. Right now I am trying to work out the issue. I have been testing the FPS and found it to be within about 4 FPS drift at 310 so I don't think air seal problems are causing the issue. Right now I think its maybe the bucking, but its just a bit of rubber so I will probably do a H nub like I did on the CM16 and the bucking at the same time.
The hop on both my G&G guns has been far from legendary, they have been a pain in the backside. I haven't yet worked out the cause of my problem on the T4-18, so I can't yet tell you what the issue is like with the CM16 where I did track it down and fix it so until I do so I can't tell you if its the unit or something simple. But I can tell you this, its my last G&G gun and I am so tempted to just sell it and get something else (The TM Scar H like I was originally going to buy).
