Just bought a Bering 2 piece and asked Chris at Smart Riders what he would recommend to keep them supple and waterproof ...he gave me a small tube (75mil) of stuff called Gaerne waterproof. After applying as directed I had several oppotunities to test this out, brilliant stuff, boots and all my other gloves have been treated and it is very good. looked for reviews on line...mostly trial riders, all good stuff. The trousers and jacket have a matt finish and at first became shiny but has now gone back to its original 2 days later, obviously needed time to soak in.
Top tip... I'll look out for it. I know people who swear by Nikwax... Personally I have always been a big fan of Renapur...
This stuff works amazingly well on leathers. I treated my leather jeans prior to a trip to Wales, where it rained heavily all the way there and back. Not one drop got through my leathers, and they are still waterproof years later. Brilliant stuff. Seems a bit pricey to start with, but one can will last for several applications and once applied it lasts for yonks.