have read some good comments on the ascend models, but never been in one. A SINK will be warmer during cooler weather since the hull will keep some of the wind/elements off of your lower body, but will be a bit harder to enter and exit the boat due to the design. A SOT will be easier to enter/exit at launch or loading up due to the design, is a bit more fisherman friendly due to the design but you can fish from either design as its done daily.
If you plan on carrying the yak around in the truck bed almost daily, then looking used is the way to go as the yak will get some rough treatement over time but you won't have much $$ in it. You could get a nicer/better one for those day long trips when you won't be traveling on business. Make sure you test paddle whatever it is before you buy to get a feel for it.
GO BIG ORANGE !
I meant to behave, but there were just way too many other options available at the time.