I used #20 for about six months and was very pleased with it. It's a good product.
I must respectfully disagree with Meguiar's on one minor point. First, a wax topper makes a HUGE difference with #20. I have a dark blue car, and the difference was simply incredible to behold. I was shocked the first time I saw it. It was so much darker and deeper! Now, it's important to note that the wax will not provide any additional protection- #20 is much more durable than #26, so Meguiar's is quite right when they say that #20 won't make much of a difference vis-a-vis protection. This is true. However, appearance is much better with a #26 topper, especially on dark cars. You might not notice anything on light cars, though.
Also, if you are choosing between #26 and Blitz, I would suggest that you try Blitz. The appearance is identical, but Blitz lasts longer. Having used both, I have to say I preferred Blitz. #26 is great, but Blitz is jus tso durable...
Second, I have recently switched to Zaino, and I am happy with it. #20 is an excellent product. You can't go wrong with it. However, I believe that Zaino offers the same benefits of #20, plus a few more, including:
1. Layerability- you can layer Zaino. No one is really sure whether #20 can be layered. But we do know that you can layer Zaino, which should give you better protection. To me, this is the most important advantage of all.
2. Swirl-filling (when using Z5). #20 doesn't do this, so far as I know.
3. Z-7 wash. Z-7 is expenisve, but it is the best car wash I have ever used. I have never had a single water spot when using Z-7, even when I wash my car in the 80-degree sun. Gold Class is an awesome wash too, and it certainly is cheaper than Z-7. I am willing to pay for Z-7 because I like it so much, but you can't go wrong with Gold Class. I still use it on my future father-in-law's car.
4. Now comes the controversial one: slightly better shine. This is very subjective, but I would say that the Zaino shine is maybe 5-10% better than the #20 shine. Zaino does not have the depth that the #20/Blitz combo had, but its shine certainly is bright.
5. Easier to use. When I used a carnuba topper, I had to wax again every month or so. This was a big pain. Blitz is very easy to use, but my car has many sharp angles, and getting the wax residue out of every crevice was a huge pain. It took almost an hour to get out, and would sometimes reappear a week or so later. Zaino doesn't have this problem, so far as I can see.
I admit that I sometimes miss Blitz. I loved it so much that I occasionally look longingly at my yellow can, wishing that I could slap a quick coat onto the Jeep. I actually use it on my relative's cars now, even though they don't really care whether I use a premium wax or Nu-Finish. I love Blitz so much that I have to keep using it!
) to improve the shine. furthermore since #20 is has cleaners in it, you'd have to re-apply #26 every time you re-apply #20.
Anyway, I have a 330i also (silver) and the black plastic trim is a concern of mine because it's a pain to remove the white residue. Honestly, I am happy with Klasse. It's just that it's very expensive and I feel that the PC pads use to much of it. I just love the protection it gives though. I thought of taping the edges of the black moldings with masking tape when using the PC and a product that stains it. 
