In my opinion, they are one of the best low-cost airlines. As opposed to Ryanair, they also operate a high number pf routes where the focus are business passengers, not the occasional leisure traveller. Having a base at Geneva almost solely for this purpose gives a bit of an idea. Unlesd you might fly to a place like Ibiza, you will fly with other folks that easily could pass as daily passengers on a Frankfurt-Zurich route with Swiss.

I've taken quite some flights with them, and never had any delays or complaints whatsoever. Their newer planes easily top almost half of Europe's legacy carriers in seat comfort (although admittedly, that's not a too high of a bar!)