It's the perfect size from my standpoint. I have worn it for 2 hours and did not have any significant fatigue. I will say that if you like to wear it tight, you might find that your earlobes hurt, as this is where the buckle is on the hood (for my setup and anatomy, at least.)
Aesthetically, it is difficult to tell the difference (from the viewer's perspective) between the wearer wearing a normal mouth cover and this particular product. That "ring" you see in the photo is definitely present on mine, but I find that it is not as pronounced, especially in dim lighting.
The gag itself is SUPER resilient. I really thought mine would have big teeth marks in it by now, but it shows very little signs of use, even after multiple sessions. You'll be happy with the durability too.
As I said earlier, the size is great. This thing does a fantastic job at muting the wearer, especially if it is pulled tightly.
Very very happy with this purchase. For what it is worth, mine came very fast (less than 2 weeks turnaround time.)
The gag is a lil bigger then I expected but still high quality n even better when attacked to the bondage hood I already have. 10/10 will order more in future