I have an Alp-X jacket and it’s washed pretty frequently (at least, by use, as I only wear it when the weather is truly grim). It’s about 3 years old now and still going strong. I have noticed that if I don’t wash it, it stops breathing and I get soaked on the inside from sweat, which is why I wash it quite often. Well, that and the wife refusing to have kit that is too filthy in the house… 🙂
Couple of tips: Wash it in pure soap (I use either Halo, or that proper Tech Wash stuff) and then line dry. Once dry, tumble it for 20 mins at a low heat. This reactivates the DWR coating so it will bead again.
I’ve just recently re-waterproofed it (just used the standard TX proof stuff) and then did the tumble drier process again. Good as new and still waterproof.