I have sort of the same question:
Can someone talk me through all the different NS models?
there are so many variations of the NS and with different prices that I loose track.
I want it to match and feel like my 3/4 scale upright acoustic bass.
two other questions:
1) how are they for arco? both playing wise and sound wise. I play arco for 80% of the time.
2) can these NS basses be played seated. I play arco in a cello like position on a lower stool.
The quick rundown:
DOUBLE BASS:
WAV - The Chinese made variant to the CR series; no longer made. 42" scale (comparable to upright)
NXT - The successor to the WAV series, which is roughly the same as the WAV series. 42" scale (comparable to upright)
CR - The higher end electric upright. Upgrades from WAV and NXT include much sturdier tripod stand, better tuners, inclusion of magnetic pickups and active 18v preamp. 42" scale (comparable to upright)
Which one of those is the best for you? It really depends on your needs. Given everything that I was going to do with my bass, I opted to spend the extra money and get a CR series 5 string and don't regret it at all. The upgraded electronics alone are worth the extra; it has a blend knob for the piezos over a switch, which I find infinitely valuable.
OMNIBASS: The biggest thing you need to know is that this one is a 34" scale bass, so if you are looking for something that will be comparable to your string bass, this will not fit your needs. Both the NXT and CR series share the same differences as the double bass versions.
To your questions:
1) The strings are going to determine how well they bow, more than anything. The OEM ones that come on it aren't really meant for arco; they sound thin and nasally. Using either the traditional set or a dedicated URB set will make it a lot easier. There's also a new NS-dedicated string set that's coming out that's easier to bow than the OEM, but not as much as a true URB set.
Tone wise, even with great technique and a good set of strings that really sing under a bow, it's going to sound like a bass through a pickup.
2) With the tripod stand, you can definitely play it in a seated position. I play my CR Double Bass in theatre pits all the time, and it's 50/50 between standing and sitting.