How bad would this be if driven on the street, say once a week in the summer. I know it adds significant NVH but will it add extra stress to anything or speed up wear on the rest of the drivetrain

In theory it could shock the trans more. In practice i doubt it makes much difference, and if so, Miata transmissions are cheap and easy to replace.

I've had a 4 puck unsprung 1.6 setup in my car for 3.5 years. It's fine. Ridiculously easy to drive as well. 10/10 will never go with anything heavier again.

Welp I guess im ordering the rigid 1.8 clutch on pay day. Been wanting the clutch for a wile now anyways just havent needed it yet. The new motor has a normal flywheel that had the weight chopped off. think it is 13#

When is the use of rigid preferred vs sprung ?

When you want the 1lb weight savings for faster shifting and more direct power transfer without the sprung hub absorbing precious tenths of a horsepower. Basically anytime its a dedicated racecar.

Rigid: Noisy, harsh, abrupt, slightly faster shifting than sprung
Sprung: Not noisy. not harsh, smooth

Thanks Emilio - convinced now that i need a sprung ...in all departments.

Geez, you couldn't have had a sale on the sprung hub? That's a screaming deal, be interested to compare the sprung hub puck to the spec stg. 3 it'll be replacing.

Would the 1.6 7.8lbs flywheel give me idle issues on my NA 1.8 with power steering and A/C on?

Yes. The A/C likes a bit of mass in the flywheel.

Just drove my new sport clutch for the first time. I got the sprung hub puck and wow is this thing easy to drive compared to the spec stg. 3 that was in it. Pedal pressure is way less too which was a welcome surprise.

Is there any break in period per say with a puck disk?

Puck requires minimal break-in. Drive for maybe a day of normal street driving and then go to the dyno if you want.

What about organic? I didn't see anything on the site about break-in time.

A few days. Don't over think it.

I've just finished breaking in my 1.8 organic with the 10lbs flywheel combo. It took me a few days to get use to driving a lightweight flywheel, but I never stalled the car. After I got used to the clutch it makes me wonder if I should have went with the 1.6 combo instead. Oh well, it's already done. There are no issues with idle, no noticeable new noises, just faster revs.
I was really surprised on how the clutch effort is compared to stock. You can feel it's just slightly more difficult to press the clutch pedal in, but not that much more. I am really happy with the effort, it makes the car feel more sporty.
The flywheel makes heel-toe downshifting EASY. I'm so excited to see how the car does now at thunderhill in two weeks.

Thank you for this feedback.

Our more expensive heat treated diaphragm spring gives us the higher clamp load without requiring a 50lb clutch pedal. That is key for use in an enduro racing car where leg fatigue is bad, or a dual duty car that your not-as-enthusiast SO might need to drive on occasion.

We like to joke that with our Sport clutches and even the Twin with the Organic discs, you can toss the keys to your racecar to your non-car-enthusiast friends and specifically not have to warn them about the clutch. There is no need for "careful with the clutch" or "the clutch is heavy, heads up".