Helper springs? NB Miata coilovers

I know that certain aspects of my question may have been addressed on a variety of other forums, but I  cannot seem to discern a reasonable answer and I always find the advice here helpful and straightforward. I'm looking at coilovers for my NB track car - I have narrowed it down to either the Flyin Miata VMaxx Xxtreme Track package or the Goodwin Racing Spec 441 Road Race Coilover.  The primary difference (at least for purposes of this question) is the use of helper springs on the VMaxx and no helper springs on the Goodwin/Feal. 

Is this important? I understand the helper spring is designed to address "droop" but I don't really know what droop is and why it's bad. Can someone help me understand the advantages/ disadvantages to running a setup with and without helper springs? 

I also welcome any input on these two choices. Car will be driven to/from the race track, will only be HPDE and autocross for fun and teach my teenage son track skills. The VMaxx are a little less expensive and I always appreciate and value Keith Tanner's input on this forum. The Goodwin's are rebuildable in the US and include extended rear top hats. 

There is also an outside possibility that I may Exocet the car sometime in the future - can't say if that will actually happen, but if one of these two choices is also better for that use, it may sway my decision. 

Thanks all 

They're not just lightweight 5-10 lb helper springs on the V-Maxx, they have an actual spring rate of something like 112 lbs. So they're really a secondary spring and not just something to keep the hardware seated at full droop like most helper spring are.  This allows for more travel overall. Once your springs are fully extended, your travel is over even if there's more shaft length available. The secondary V-Maxx spring allows for more spring to be packaged.

A bigger difference is the fact that the Feal are a two-piece shock body, which means a shorter shaft and more potential for getting the setup wrong. That could be one reason they require an extended upper mount, they're trying to get a longer minimum length shock body in there without giving up bump travel. The V-Maxx gives you about as much bump travel as you can get out of the suspension control arms, an extended upper mount will cause contact between the control arm and the subframe which is why we don't offer it. But because they're a one-piece shock and can thus package a longer shaft, you don't give up any droop in exchange. There's a lot of really, really bad information and outright misinformation about the "benefits" of adjustable length coilovers but a lot of it comes down to them being cheaper to make because you can more easily use off-the-shelf parts. 

The lack of rebuildability is unfortunate with the V-Maxx, but that is a tradeoff for the lower cost of entry.

Droop is how far your suspension can extend - when you have the car on jackstands and the wheels are dangling down, that's maximum droop. Bump is the other direction, it's how far you can compress the wheel into the wheelwell. Bump is more important on a track car, but if you don't have enough droop you'll find the car losing traction coming off sharp corners and a much less stable behavior going over crests at speed as the suspension runs out of travel.

I've not tried the Feal, but I know the V-Maxx work well on an Exocet. The Exocet in this article was running on the XXtreme Sport. BTW, this article is a great read for anyone, it's good fun.

https://www.roadandtrack.com/car-culture/a32131/miatas-at-mazda-raceway-miatagasm-mega-test/

Great thanks Keith - exactly what I was looking for. Now just to get past the other problem - waiting for the VMaxx to come back in stock! 

They're working their way across the US now :)