I cannot speak for a 718 yet as my Cayman is currently in production.

I owned a 30th AE Miata and currently have a 24 BMW Z4. Both are front engine RWD and both cars feels very different. The Miata felt light and nimble in corners, however in terms of acceleration, it feels like a Corolla. High rev is required for the engine to perform. On the other hand, the Z4 feels solid the moment you open and close the doors. The power delivery is much quicker. However you feel rear end is more playful in corners. The build quality of both vehicles are good. If you want to drive a slow car fast (which is more fun), the Miata is able to deliver that. However if you want to drive a fast car with an exhaust tone, I have no doubt the 718 will not disappoint.

 

To add to the confusion.

In motorsports applications, I've seen chassis referred to the primary structure more often and then suspension and vehicle dynamics are their own entity but to me that's more on body structure rigidity and mounting compliance being significantly more important in racing as that will negatively affect lap times.

Outside that its a hot mess and I've used chassis more for the overall handling of the car since most normal road cars body structures prioritize safety over minimizing compliance.

 

I had a 2005 S2000, loved it, but when it came time to get another sports car there was no comparison. My Cayman S is even more fun than the S and that is saying something as the S is a better car than the Miata.

 

I had an S2000 back in the day. Fun little car. It was fun to rev to 9,000 RPM but had minimal torque down low. All the power was between 6000 and 9000 which is crazy.

 

Here's a pic of my 2007 that I purchased from my dad when he got to the point he could not get in and out of it any more. It was bone stock when he sold it to me. It was fun to drive but i knew I could improve it so I installed a turbo (280 HP), limited slip diff, coil overs (lowered it a bit), bigger wheels and tires, rear spoiler and some graphics to spice up the looks. Very fun to drive and all aspects of the car much improved. But, just does not have the refinement of the 718. And though it handles great, not as confident inspiring at the edge like the 718.

 

To date, the MX5(NF) remains the car that has given me the most driving pleasure. The Boxster now allows me to write the next episode.

 

Porsche is lux cruiser car, miata is a fun nimble sport toy.

 

Pics of your car?

Both are nimble sports car toys one being a much more capable daily car than the other

 

The MX5 ND is the car that left me with the best memories. Lively and agile, comfortable for a sports car, very well equipped, and economical to run. My only regrets: a trunk that limits trips to five days and is a little cramped for my 6'0".
The Boxster gives me similar pleasures, but without the flaws (except for the maintenance budget and the risk of losing my license).
Between the two, there's the Mini JCW.

 

The MX-5 is the ultimate iteration of the 1960s British sports car; small ,light, front-engined, modest power.
The 718 is a much more modern mid-engined design, with better suspension, brakes and steering.
The comparison is not really fair.