Because it is possible that technology and manufacturing methods have moved on from what are described as OEM NA6. > 20 year old coilovers.
In the same way that a new set of YS/BC coilovers are going to perform better than a set of 20 year old OEM Bilsteins and come with warranty to boot.
I don't see why you think it is appropriate to waltz in making those sort of comments.
btw. Rims are a very different thing to a set of coilovers,
I don't know where to begin answering this, without sounding harsh and pushing a particular product but i'll try.
Often aftermarket coilovers ARE harsher than the factory suspension, this is because of the functional aspect. They are designed to have different perches heights spring rates, dampener settings.
I have various friends with mx5s, each individual owner has individual tastes. Many have yellowspeeds, the basics or premium comps, many have Tein streets or flex and others have Bilstein pss9s or Ohlins.
There is a DEFINATE difference in quality between each product, this is due to the countless hours of R & D the premium manufacturers put into there product. Each is different in every application.
The argument about Rota > Works wasn't because of real or fake, it's the value for the product. I am fully aware the differences between wheels and suspension.
There is a reason many people on this forum and others similar often trade used Yellowspeeds, outside of the cost. It's because they are designed to be an entry level coilover and many people have higher expectations based on reviews.
You don't often see used Ohlins or Teins being traded because there owners are generally happier and have no need to remove them. I have a good friend who runs the Yellowspeed Premium comps, he cannot lower the rear to a height he would like (it's maxed out) and when he sits in my car he noticed the difference between my suspension and his own, enough to mention it each time. It's my softer springs that I think make the difference.
In the same way that a new set of YS/BC coilovers are going to perform better than a set of 20 year old OEM Bilsteins and come with warranty to boot.
There is no guarantee your new coilovers will perform better than the OEM equipment. It would depend on there purpose. To lower the car they would be much better, but on a rough road they could be harsher as the spring rates from factory where softer and the dampeners where not set as hard.
It's appropriate to mention the above because many people such as yourself lack the foundation knowledge and spread so much bullsh!t with no proof and I would hate Kev to buy an inferior product due to lack of information.
On the topic now, I think they are a steal @ that price.