I'll give my initial impression of the Yoko Parada Spec X. I've had them on for about 3 weeks now.
Looks. Tread pattern is way more aggressive than the Pirellis, it also looks as if there are holes to insert studs for the winter if you want. I like the look and I would say that they look like they will be able to handle wet and snow better.
Ride. Ride is much improved over the Pirelli run flats, but that is to be expected with the softer side walls. Still a "firm" ride, but less firm. I like the change. I also noticed a lot of "tramlining" with the Pirellis when they got worn down, but again this is a common problem on run flats. High speed jostling has been eliminated on rougher roads, feels more planted.
Noise. These are quiet as a church mouse currently.
Handling. Ok, the real test. The first 100 miles the tires were slick, real slick. As they wear in though, they are getting much improved. The tires now feel solid in turn in and harder cornering. I will say though that there is more roll in cornering (again expected with the softer sidewalls) but the tires seem to stay planted. I have not yet really pushed them in cornering, but initial feel is that they do not give you as much confidence as the run flats did. However, again, they seem to stick just as well with no increased understeer. I will push them harder and report back. Dry traction is excellent, as is wet traction.
So, final assessment is that I think the Pirelli run flats give you more driving confidence with less body roll to the Jeep, but the Yokos do seem to hold corners just as well. The more I drive on them, the more I like them and the more confidence I get in them. For less than half the price, this is a no brainer to me. Get the Yoko. Yes, they are not as highly speed rated as the Pirelli, so if you are going to be doing over 150mph, stay with the Pirelli. Me, living in Pennsylvania I'll never get over 110 or so.....if I'm lucky so the 149mph rating is not an issue.
Rating. Buy, especially if money is a consideration.