We build with lots of their hubs and have not had many issues with them. The bearings in the rear hubs may not last if you ride much in the wet. They are easy enough to change out and AC will have full stainless steel bearings with a different grease available in the near future. The front hubs have never been an issue but you should check the adjust when you first get them. Again, it is very easy to check and fix.
Let me know if you have any further questions on the hubs.
They're not always adjusted as good as they could be but an axle vice, two cone wrenchs and 15 seconds is all you need.
The axles have been holding up just fine and the SS rear hubs do come with a steel cog (18t I believe) and spacers. They are available as bolt-on or QR but the bolts they use are very heavy and very cheap. King Fun bolts make a nice replacement but aren't any lighter.