ComfortEven when using this mat for an extended period of time it was still comfortable to use. This is mainly due to the fact that the pad is so thin (2 mm). Because it's so thin your wrist is really close to the pad surface making it comfortable to use compared to other relatively thick hard plastic mats.
DurabilityLike with most hard plastic mats, the SteelPad S&S is quite durable. The surface is about as durable as any other hard plastic mat on the market, the only real durability issue that this pad has is the grip-layer applied on the bottom of the pad to make it grip the desk surface. Just like with the old one it's made of rubber that is "sprayed" on the the bottom of the mouse mat, this has a tendency to roll up and peel off after some time.
My thoughts on the grip-layer are undecided, on the one hand it provides excellent grip to the desk surface but it is a real durability downside. You can actually scrape it off with a fingernail off the edge or your table. Of course this is considered abuse. But I guess at the end of the day when I am playing an important match I would rather have the mat staying in place than slipping around even though I had to buy a new one every year or so.