From all reports the valve stems are vastly superior to a lot of long aero style valves out on the market and seem a bit more durable without the weight penalty.
The bike came with Kenda 18-23s oem and I had stem problems from the get go.
Most of the lBS sell generic brand (or at best Bontrager)tubes. The rolling difference with generics was noticible.
Figured IF Specialized were available I'd give em a try.