I think it's good for casual N64 fans. It's affordable, more traditional, and has decent build quality. However, as a hardcore fan of N64, I find it lacking for a few reasons.
The joystick, while more durable out of the box, has a different sensitivity than the official sticks. Again, casual players might not notice this, but play something like F Zero X on master back to back with the Brawler and an official controller in good condition and you'll see exactly what I mean. The controls in many N64 games are fine tuned to be played with the official stick, and feel slightly off with other controllers. Also, the more traditional layout of it doesn't lend itself well to some of the more ambitious control schemes in some games. For example, Goldeneye has a control scheme were the D Pad acts like WASD and strafes in 4 directions, while using the control stick to look in all directions. This works basically identically to a modern console FPS game, and it's my preferred way to play the game. However, the Brawler puts both the D Pad and control stick on the same side, so you have to go southpaw and use the C Buttons to strafe and the control stick to look.
So I do think the Brawler is a good option for people who can't get used to the unique (but still comfy IMO) shape of the official controller, or people who just want a cheap controller that works mostly well without any adjustments. But for more serious players, I'd recommend following this guide to repair N64 control sticks.
https://www.youtube.com/watch?v=ETQhlSXIsR0 I did it to my controllers years ago, and not only did it make them feel almost brand new, but they still feel perfect after tons of usage.