M45 Supercharger Kits?

Does anyone have experience with the G19 Engineering Miata supercharger kit? I'm curious why anybody would want the "dual throttle body kit," and I wonder how the kits perform in the real world. 

I'm thinking of this over a turbo because it looks simple, I have had several turbo cars in the past and I much prefer NA throttle response, and because it looks like something I could conceivably swap on and off in case the inspection people give me trouble. 

Thanks

I had an M62 supercharger kit on my last NB. It was a single throttle body, and it would drop the idle RPM until it fully warmed up. It was a bit of a PITA every time I came to a stop. My understanding is the second throttle body cures that because it's in the stock location and effectively reduces the intake tract volume.

As I understand it, it basically it prevents off-throttle throttle lag. With the M45 mounted so far away and an intercooler that's filled, you let off the throttle and the long intake tract is still pressurized. 

In reply to NickD :

Which is absolutely amusing to spectate when the Miata is set up to control cornering with the throttle.

Much flailing ensues when the driver lets off the throttle but the engine keeps going for a few seconds.

The key here is that unlike with a turbo (or centrifugal supercharger, which is basically just a turbo driven by a belt instead of exhaust), you really can't set up a positive displacement supercharger to blow through a throttle body because of the backpressure when the throttle closes.  So the normal way to do is to relocate the throttle body to the inlet of the blower, but that creates a large "throttled volume" which hurts off-idle throttle response.

OEMs solve this by using air/water intercoolers integrated with custom intake manifolds to minimize that volume, but that's something that's hard to do in a cost-effective way with the low volume sales of an aftermarket kit.  Mounting two throttle bodies (one on the inlet to the blower and one in the normal place) has been proposed as a solution, but I don't have any firsthand experience with how effective it is.

In reply to codrus (Forum Supporter) :

Ford and VW did blow through positive displacement superchargers.  I forget what Ford did on the Thunderbird SC (which had an M90), but Volkswagen had a double throttle on the G60 engines that was basically a mechanically linked bypass.

Mercedes did blow through M45s but they used a clutched blower because they like to overcomplicate things.  Same for Toyota on the supercharged MR2s.

It sounds like there are better solutions if I want throttle response and predictability.