We did a blinded randomized controlled potato chip tasting trial (RCPCT) yesterday. Unfortunately, everybody wanted to participate and therefore, we could not do it in a double-blinded fashion. We went for the plain type, for which we could find in Prisma three different brands: Estrella, Taffel, and Xtra.
We only evaluated taste, and the results were clear and a bit surprising: Xtra and Estrella shared the first place and Taffel took the third/last place in the opinion of all four contestants. Given the fact that both Taffel and Estrella are almost twice as expensive (8.49€ and 8.18€ per kg, respectively) as the Xtra brand (4.3€/kg), it seems to be a no-brainer to buy the Xtra brand. What about nutritional aspects? Both Estrella and Xtra have 1.4% salt, while Taffel gets away with 1.1% salt. And the fat? Xtra uses exclusively sunflower seed oil, while both Taffel and Estrella use a mix of sunflower and rapeseed/canola. Consequently, Estrella and Taffel both have a healthier fatty acid composition that Xtra, and Estrella takes the lead with the least amount of saturated fatty acids.
Which one to choose is not really clear: You get good taste for the least money buying Xtra, but it's not the most healthy choice. On the other hand, it is not really clear whether Taffel or Estrella takes the lead in the health category (if we can speak about such category when evaluating chips at all). Taffel has less salt, but more saturated fatty acids. Estrella has more salt, but less saturated fatty acids. Since the price is roughly equal, let the taste decide.
PS: Both English and German do not distinguish between the two different Brassica species, that are used to produce rapeseed/canola oil (Brassica rapa and Brassica napus). However, in the Finnish language, Brassica rapa translates into rypsi, while Brassica napus translates into rapsi. The nutritional values with respect to the fatty acid composition are similar for both plants.