for what it's worth, there isn't much turbo lag if you choose the right turbo application. a small pair of turbos would spool up rather quickly, versus a big single turbo which would make even bigger numbers with a little lag while it's spooling up. however, that's largely dependent on your driving style and application. for instance, the turbo drag racers usually have automatics and build up the boost so they're leaving the line with full boost and lifting the front end off the ground.
However, depending on where you are, turbos are not smog legal just because they're turbos. California and many others are the case because you're putting something that sits between the MAF and catalytic convertors, and could possibly make the car run differently than it shipped. I'm not a big fan of their idea and smog limits, but there isn't much that we can do about (other than register your car in another non-smog state ).
It's all about what you really want out of your car.
It's also rather hard to argue about the pricepoint of a centrifical blower. Paxton, Procharger, and Vortech are all rather cheap, come with nice kits, and are rather easy to tune. The same can be said about Kenne Bell and Whipple Twin Screws, however they are a couple bucks more. I've got to say that the Vortech kits are pretty nice, and have a large following where you could likely grab one used for half the retail price. I grabbed a Novi 2k with intercooler for $2000, and my buddy just sold his V1 S-Trim full kit (complete with a Snow kit) for $2600.
The Vortech line is nice because they've got a couple of different offerings. The V2 SQ's are really quiet at idle, spool pretty quickly, and they've now got V3 blowers which are entirely self contained and no longer require punching holes in the pan. Alternatively, the Twin Screws are also rather quiet on idle, and give out that patented whine when stomping on the gas. I guess it's all up to you, as similar power levels can be had on the same boost. The beauty of superchargers are that they are a true bolt-on, 4-5 hours of work, and you've got a supercharger ready to go. Can't exactly say the same for the turbos.
Good point. The new turbo tech. is really sweet.