Toronado
So I see a car that is faster in every way for a grand and a half more. Not to mention things like trunk space, build quality and such. Now, let me get this straight: The Kappa cars are great, the Sky being the better of the two (but whatever), but the fact that they weigh 400 lbs more do not make them a good competitor to the Miata. Also, it's great that they offer faster versions, but said faster versions add even more weight to the already portly car. The Miata is known for it's quick reflexes and tossabhle nature, and in every review that I've seen there as a criticism of the Solstice that it weighed to much to be truly tossable, which is the Miata's #1 quality. I really don't care how fast they go, because they don't make up for the fact that they weigh to much to be able to out-do the Miata at what it best at. The only car that has done that since the Miata launched was the 3rd gen MR2.
You're joking right? How is it faster in everyway...I just pointed out the specs? If you're going to quibble over 0.1 seconds to 60mph and 0.2 seconds in the 1/4mi then seriously you are way too biased. Even the 0.01g difference in lateral G isn't that much. Those kinds of tiny differences come down to weather and or the driver. And as for the hefty comment, the top of the line Solstice is less than 100lbs heavier than the base model. That's nothing.
Storage space? I don't think the Miata wins here, it's more like a tie.
2006 Miata:
Front Head Room: 37.4 in. Front Hip Room: 50.6 in.
Front Shoulder Room: 53.2 in. Front Leg Room: 43.1 in.
Luggage Capacity: 5.3 cu. ft. Maximum Cargo Capacity: 5 cu. ft.
2006 Solstice:
Front Head Room: 38.5 in. Front Hip Room: 50.6 in.
Front Shoulder Room: 52.4 in. Front Leg Room: 42.7 in.
Luggage Capacity: 5.4 cu. ft. Maximum Cargo Capacity: 5 cu. ft.
Exterior dimensions. So the Solstice is wider and longer, while the Miata has about 1 inch height difference. The Miata has about 0.1~0.3 in. ground clearance advantage. So again I feel this is a tie...wider and longer makes up for extra height and weight in the Solstice. And the extra 362lbs the Solstice has really isn't that much more, especially when it has the extra power to compensate.
2006 Miata:
Length: 157.3 in. Width: 67.7 in.
Height: 49 in. Wheel Base: 91.7 in.
Curb Weight: 2498 lbs.
2006 Solstice:
Length: 157.2 in. Width: 71.3 in.
Height: 50.1 in. Wheel Base: 95.1 in.
Curb Weight: 2860 lbs.
Build quality?
We will have to wait at least 3 years to gauge an ACCURATE opinion on the Kappa's build quality. So this point is not debatable until we get the longterm figures in for the Kappa.
Now, playing Devil's Advocate here the Miata wins in the trim levels (has 6 I think) and gas mileage. The reason for the better gas mileage IS because of the lighter weight and frankly I like Mazda's engines more than anything from GM with exception to the LSx V8's. The Miata's biggest draw is it is it has been the roadster of choice for the less than $25k market for the last 17 years--it's proven and like an old lovable dog. And the Solstice is like the young pup that has to earn the respect of the older dog. The 3rd gen MR2 while ugly is a great roadster itself...but I'm not bringing that into the debate because more people own Miatas and it's not part of the meat of this debate.
So in conclusion I honestly believe these are two very close competitors. It's clear by the numbers that they are, I just don't see how anyone can get a clear victory for either of them.