Bolt necks are just different. People often talk about a neckthru having more sustain; on a loud bandstand, ANYTHING will sustain at volume. Having owned both (and swearing off bolt necks from now on for several reasons) the REAL difference is that neckthrus carry more fundamental and 1st harmonic into the signal going to the amp. You can even hear this unplugged by playing an open string and putting your ear to the upper horn. This happens whether its fairly common woods (maple, alder, mahogany) or some of the more exotic menus from ALEMBIC and others. And passes this through to whatever pickups/electronics are on hand.
All the Smith players I can think of are pop/funk/slap guys. I can't think of any deep groove guys who use them.
Smiths remind me a lot of some other brands that are great for that boingy, slappy sound. Which reminds me of a classic case of that sound at work I once saw, and learned a lot from:
Modulus Six through a nice Hartke stack with effects, and a first rate guy playing this setup. Had that real 'new string' clangy sound, lots of high bass/low mids and plenty sizzle on top. Would have been a nice tone for certain types of recording, but was COMPLETELY useless playing with a dance band: NO BASS to lock up with the kick, no anchor, no groove to dance to.
Sound familiar?
The Smiths I've tried were nice axes. Sounds like you're gonna have to rethink your sound, new amp settings, different strings, etc. I'd consider a 15 and get REAL familiar with the 50 to 200hz range on your rig!
You now get to learn how to take lemons and make lemonade!!! But hey, you're talking to a guy that's shot himself in the butt more than once when it comes to equipment choices, it happens to all of us. I'm sure you'll find a way to live with your KS, whilst saving for another ALEMBIC.
J o e y