I speak as a former owner of a PRS bass. I don't know why they do such a nice job on the guitars in terms of design, sculpting and aesthetics and haven't ever put the same amount of effort into the basses. The exception is the handful of early shop-PRS basses and the Granger which was never a real large production model as far as I can tell. Side stepping some of the tonal problems of the past series of PRS, it would be nice if these didn't look like an afterthought or like every other cookie-cutter import slab.
My PRS played and felt amazingly good...to me it lacked in the looks and design and had some very obvious issues with the electronics and end sound.
Yeah, that was my experience as well. I had #40 (since sold) and while it felt nice and sure got a lot of sounds, I didn't find any of them to be all that pleasing. The finish was, well, vanilla. The moon phases inlays were actually pretty cool and understated. But overall it didn't really scream PRS. I wanted to like this bass but in the end I just never used it.
That said, I think that doing a SE series for bass is a cool idea. An SE 5-string Grainger would be very tempting!