I have a Highway One P Bass which has a neck which is a little over 1.6" wide. I noticed the SB-2 has a 1.5" neck which I prefer.

Can anyone here give me a comparision between the two as far as tone and playability?

Do you get a true P bass tone with the SB-2 and what does the bridge pickup add as far as versatility?

First of all, you should read this thread over on BABP:

http://badassbassplayers.com/forum/viewtopic.php?f=48&t=6645

I have an American Series Precision and a U.S. SB-2, so I'll give my views, with the caveat that my P-bass has a maple board and rolled fingerboard edges, so it's slightly different from a Highway One neck.

Playability-wise, they're very close. The SB-2 has a narrower nut, but the neck profile is meatier than an Fender Jazz, so it actually feels close to my P-bass. (And maybe even closer to your Highway One.) I prefer my Fender's neck, which fits me perfectly, and I like the rolled fretboard edges, which G&L's apparently have now. I also generally prefer the feel of maple fretboards, and my SB-2 is rosewood. But my preference for my Fender isn't too strong, and it's not a quality issue. If I could get my SB-2's action a little lower it could move ahead.

Tone-wise, the SB-2 blows away any Fender I've heard with a stock Fender pickup. My P-bass has a Lindy Fralin, which sounds similar to the SB-2's split-coil, but the latter has more lows, more highs, and humongous output. But that classic split-coil tone is in there too -- genuine vintage vibe courtesy of Leo. I love it. The bridge pickup does add some definition to the split-coil's tone, and increases the versatility. The SB-2 lacks a tone control, which decreases versatility on the other end, by limiting the old-school thump unless you adjust your amp. No biggie -- just adjust the amp! And it "whumps" more than it "thumps." It's a bigger tone all around.