I received my UHS system last week pads & polish. Haven't had a chance to use it yet but noticed the pads are quite a bit firmer than I would think.
They feel stiff not at all like a polishing pad but like an aggressive cutting pad.
How does that pad produce a final shine?
Keen observation and you're 100% correct. The pads also hold their rigidness or stiffness for a while before softening up as you continue working a single pad. I don't know if Rupes has an official recommendation as to how many pads you should use for any specific car or an official recommendation as to when to change to a clean, dry pad.
I do know from use that the longer you buff with a UHS pad it does start to soften up with product saturation.
I used and abused the pads on the blue Ferrari to test and push them to their limit for my own knowledge. That said, my normal practice and what I've recommended on this forum for the last 5 years is that...
More pads are better
That means, it's faster when buffing out a car to be able to switch to a clean, dry pad after buffing out a panel or two with the current pad.
That means for an average size passenger car you want a range of 6-9 pads. For example, buff out the roof, (usually a large panel), and then switch to a fresh pad when you tackle the hood, (usually a large panel). You can tackle both panels with one pad but you'll see the performance of the entire process diminish with any foam pad on the market as the pad becomes wet with product.
So it's alway faster to switch to a clean dry pad often and in my opinion especially for what I call the Gloss Panels in my how-to book The Complete Guide to a Show Car Shine (and I explain why).
Also, by using more pads when buffing out entire cars for a full or part time detailing job, you'll get more use out of the pads overall as you won't be punishing them as much trying to get as much use out of a single pad in a single detailing project before switching out to a dry clean pad.
That's the pad side of my answer to your question.
The more important question is answered in post #14 of this thread when Mark aka ZL1 Mark asked,
If it was designed for hard clearcoats, I would assume it may not finish as well on soft paint systems?
And I answered...
Mike Phillips said:
Never assume... always do a test spot...
It's worked on everything I've used it on so and I haven't really heard about any negative experiences. Time will tell.
I have a few more projects coming up, all with custom paint, not factory paint so hang tight...
This system was made for hard clearcoats and this means both the pad and the polishing compound could potentially NOT finish well on all paint system and especially softer paint systems.
So always test first.
Good question.
I don't think my wallet cannot afford another system and I am running out of cars to polish. Maybe when the current supplies run out and I get bored. 
