I’ve got an Extreme 4, had it for 5 years and absolutely love it. The neck in particular. Nice C profile, thin but not too thin, and the satin finish is ridiculously smooth. Fit and finish is great and set up was good out the box. It just feels so nice to play. If anything the sound is the weak point (not bad, not terribly exciting), but I mostly play alone through headphones so can’t weigh in too much there.
Take the gushing with a pinch of salt as this was my ‘upgrade’ from a piece of junk and is my only bass. I did go and try out some potential swaps recently and far preferred mine to a Player Jazz, Mustang and Yamaha TRBX…nicer neck and the quality just felt better. Its actually annoying because I’ve kind of grown out of the fancy inlays but looks like I’m stuck with this thing forever!