Now for the more "update" type of post.
TL;DR up front: Opti-Coat reigns king and nothing can touch it.
Over a dozen applications of Opti-Coat has taught us a lot, but more than anything, time has been the ultimate test. After all, we're not talking so much about shine, gloss, ease of application, or price as much as we're concerned with durability when using one of the "coating" products.
I've seen Opti-Coat stand up to quick detailer, alcohol, mineral spirits, washes, and more than anything; time itself. The product is amazing. I've even seen David Fermani's test car in person after a thousand mile road trip through bugs and bad weather. There was a very clear and definite difference in the Opti-Coated side versus the bare side 18+ months after application.
With the emergence of Opti-Coat 2.0, the product is even easier to use and results in less streaking problems.
With using any version of Opti-Coat, we've found it to be easier with two people (especially with version 1), with the second person armed with CarPro's Reload and a suede style microfiber towel. Not only does this take care of streak marks, it seems to give the finish a more silky feeling.
CQuartz has been used one two vehicle which were closely watched. First, my wonderful girlfriend's Saab 9-3, in which it didn't last 8 months. The application and issues we had are clearly laid on on page one. Wanting to give the product a fair shot, it was also used (by request) on the "cleanest GTI" which is here:
http://www.autopia.org/forum/click-...nest-gti-stepping-up-our-game-autolavish.html
We're over 6 months out after having worked on that vehicle and there's no appearance that the CQuartz is still there. We have 100% confidence we used the product correctly, and I have personally washed the GTI twice since detailing it (using Reload post wash each time), and I'm amazed by the lack of tight beading, lack of slickness, and the amount of contamination the finish is getting despite being garage kept. If these weren't the EXACT same issues I had with the 9-3, I'd think maybe we did something wrong. In reality, durability is nothing impressive and we won't be ordering more of this "coating."
Gtechniq C1 is the wild card. In direct talks with GTechniq, we've found the C5 "Wheel Armor" is basically the same product as the C1. This is important to note as we used the C5 on the wheels of the GTI linked above. The problem is the owner sold the stock wheels and has new wheels on it that we didn't coat. In short, I can't confirm or deny durability of any kind of C5/C1 when used on wheels.
Paint is also a problem. The Maserati Gran Turismo C1 was used on was sold prior to our 6 moths "check-up." The only saving grace is we applied it to our new work vehicle (Honda Element SC). The Element was polished and Opti-Coat 2.0 was applied on half, to include half of one of the front wheels, while C1 was applied to the other half, to include half of the other front wheel. Incredibly, we can see a defined line on each wheels still and half of each has remained clear the the non-coated sides. While this vehicle was done a month and a half ago, it hasn't been washed since, so I can't give an update aside from that.
Take away what you want, and if anyone has questions, I'll try to help answer them appropriately.