I need to replace the air springs on my 2008 X5. I usually stick with OEM parts but I was in the auto parts store the other night and out of curiosity checked the price of air springs there. They carried Arnott springs:

https://www.arnottindustries.com/par...21_pid198.html

the price was pretty much the same but they have a lifetime warranty so (presumably) if these fail in another 5 years / 60k miles I could get them replaced.

I'm changing these out myself so the warranty is definitely appealing but I don't want to regret going non OEM either.