Re: permanent stretch, my assumption was that there would be LESS permanent stretch, but the sales associate said it would be about the same. I haven't worn mine enough to comment on how/if mine have stretched.
I recently bought the Shockoe denim that has 2% elastane, and I absolutely love it. First denim I've owned with "stretch" and really only stretches when I need it (like when bending down and crouching)
The J1B is awesome (styling wise), but it's actually not super technical. Pretty basic cotton, somewhat heavy feel, no gore-tex lining so not waterproof. It's still my favorite style-wise, but wouldn't be my first pick up. I went in to Darkside to pick up the J1B and left with the J25-WS instead