From a bullet-point point of view the CR4 has (that the wav does not)...
- preamp
- pan pot for the two piezo pickups
- the higher quality tripod
In materials the CR has (
http://www.nedsteinberger.com/instru...rbass-spec.htm)
"Solid rock maple neck and body, flame maple face"
"FINGERBOARD: Macassar Ebony"
"NUT: Macassar Ebony"
"BRIDGE: Black phenolic"
Double truss rod, Schaller tuners
Versus the WAV with (
http://nedsteinberger.com/wav/closerlook.html)
"Solid beech wood neck and body"
" Fingerboard Ebony"
"Bridge Rock maple (dyed black)"
"Nut Macassar Ebony"
"Truss Rod Powerful rod design provides positive relief adjustment, accessible at nut."
"Tuning Machines Fully encased worm gear tuners (black finish)"
And more subjectively.. I have a CR4M bought a bit before the WAV came out. I keep trying WAV basses every time I run into them. They sound ok compared to the CR, but I still prefer the CR. Blending the piezos is nice. The materials do seem to be nicer in appearance on the CR, but I don't know if that equates to greater durability or not.
I'd say the CR is definitely worth it, but the WAV is as well. The true test is to try out both of them with your preferred amplification. If you like the CR more, hold out. (:
IMHO, IANAsalesperson, etc.