I'm in the market for my first (real) p- bass. I've only been looking at fender American, and a few nice mij ones. How much better, really, is an LB100? Other than having a six bolt neck, which I do like, the only improVement I see is the better pups & bridge. What else am I missing?
Compared to a Fender P bass, the LB-100 has an extra fret and the pickup is slightly closer to the bridge. The tone knob works really well to control those extra highs you get, I'd leave it around 8/10 for a traditional "open" P sound.
Other than that G&Ls have a Plek job which makes your frets super level and buzz-free. They also have aluminum post tuners (lightweight) and a bone nut. Pickups are like Fender Custom-Shop quality.
G&Ls can be ordered custom for about the same price as one in stock as well (depending on the retailer), so you can pick from several neck profiles and sizes. You can order a LB-100 with a Jazz bass neck, or a baseball bat, or a modern P neck in three different fretboard radii. You can order a G&L with a quartersawn neck or not. Then you can pick various color schemes and woods for the headstock, body, neck and fingerboard.
G&L operates like Fender did in the 1950s and early 60s, with the small shop that takes custom orders and whatnot. G&L is also a Leo Fender company like Fender Co. is. Arguably G&L is sort of back to those Fender roots with that small shop / innovative feel.
I don't think Fender offers Plek jobs on any of their instruments. Their bridge design is also very different. The saddle-lock bridge has a lip of metal deep in the body that seems to make it resonate through the wood well. They also allow you to keep the saddles free-floating, or you can use a screw on the side to lock them together, in-place.
For what it's worth though I think G&Ls most impressive innovation are the MFD pickups. I am quite partial to their basses that use those, like the SB-1 or SB-2. They sound like low-impedance pickups, retain plenty of highs, but are quite high output, and yet operate completely passive. The design gets them something like 4X the output per coil wind so they don't have to wind it as hot for more output. So you get high output but clean sparkly highs.