A big fat downhill tyre that won't let you down. It holds a lot of air which means it's very bouncy and can roll over many smaller obstacles without throwing you off.
Strengths
The tread pattern chucks dirt and mud leaving it to do what it does best. It has a large air volume which means it'll soak up a good ammount of smal bumps and lumps. This also means it's great for hopping.
Weaknesses
None to speak of.
Overall
I got one of these when I ordered my Pashley MUni from Unicycle Source UK. Put the Gaz next to the stock one that comes with the Pashley and watch the latter try and crawl away in shame with its head in its hands and sobbing like a baby ;-). This is a beast!