Yeah - I've used all of the products you've mentioned (Werkstatt, Duragloss, NXT, S100 and Collinite - as well as several others like Klasse and Zaino) - and out of all of those Werkstatt is my pick for the best combination of looks, durability and price.
S100/P21S and NXT look great (and have some ability to hide swirls) but are not good on durability. The NXT also stains trim like no one's business.
Collinite and Duragloss 105 are both very durable, look great and are well priced - but I prefer the Werkstatt look. I do use Collinite 845 IW on my wife's van and I use Duragloss AW on everything. An extra selling point for Collinite 845 is that it contains oils and fillers and does a pretty good job of hiding minor swirls/marring. Werstatt, Zaino, Klasse and Duragloss do not hide marring at all. If you need something that will hide swirls, then Collinite is probably the all around champ for looks, durability and price.
Klasse is durable and well priced but doesn't compare to Werkstatt in looks IMO.
Zaino may be the best looking product out there and is incredibly durable, but is not as reasonably priced as Werkstatt.