blkZ28Conv.
I used the NXT Car Wash today for the first time. I was pleasantly surprised with the product. It is not Sonax, and I haven't tried the !Z products yet, but it performed admirably at its price point ($5.67/64 oz. vs $7.99/64 oz for GC). Based on my first time experience, I'll respond to your questions:
Lubricity - Definitely a step below Sonax in this category, but so is the price. The solution feels "thinner" than GC, but not lacking. I felt comfortable washing the vehicle which was moderately dirty (muddy) on the lower panels and a pretty good covering of sticky pollen/water on the upper panels.
Cleaning ability - The car came clean without requiring excessing rubbing/scrubbing. That said, I can't recall an instance where a car wash didn't clean adequately even the dirtiest of vehicles.
Protectant disruption - The vehicle in question had 2 coats of PUPP. Following the wash I QD'ed with PUGE and the surface was nice and slick. Again, I guess I haven't experienced the phenomenon of a car wash disrupting my protectant. As with you, I apply my protectants often so I guess it would take a Dawn wash to present this problem.
Rinsiblity - Very good. As mentioned in the "Lubricity" category, I feel that the "thinner" feeling solution rinses much easier than GC. This is evident not only on the finish, but in the rinse bucket as well.
Suds - Plenty. Enough to last through the end of the wash.
Unlike III's experience, my initial NXT Car Wash experience was quite favorable. As I go through the bottle, I will continue to assess it's place in my kit.
As a point of reference, these are the other washes I am currently using:
American Shine Carnuba Car Wash
Blue Coral Super Foam Car Wash
Meguiars Gold Class Shampoo
Meguiars NXT Generation Car Wash
P21S Total Auto Wash
Pinnacle Bodywork Shampoo
ProtectAll QEW
Sonax Gloss Shampoo
Zymol Auto Wash
HTH