Solvent base poly's are a thing of the past, they go yellow, off gas way too much toxic stuff, they are strong.
Europe is heavily into hardwax products, be careful I used Osmo Hardwax and it was the WORST product I ever used (I have been meaning to put a topic up here about this disaster product)
I have used other hardwax products and they have performed as the manufacturer promised, I do believe they don't like being applied in colder weather as they cannot set properly.
Last few floor I have done, I used waterbased 2 part Intergrain product, the floors looked great, they don't do this product anymore and only have one called Ultrafloor.
Even though they were water based and said they didn't yellow, they did slightly yellow over two years, but still looked quite clear