I have a Mk1 and Mk2 "stealth hoodie". The rhino-hide material is pretty good. my Mk2 made with the rhino-hide is still in good shape and it has had a great deal of use.
Weather its worth the cost is really up to you to decide. The jackets are waterproof, wind proof, light weight, well designed and have fairly high production standards so they are good.
I did have some problems with the zip on my Mk2 when i first got it but the jacket was replaced so i'v no complaints really.
They do seem to improve there products as they go through the Mks, i see the Mk3 has reinforced elbows and pit vents so it seems to be a slight improvement on the ones i have.
These jackets are just a shell though, you do need a good flease etc. to keep the heat in during cold weather or at high altatude.
