Just purchased Cognac & Dark Brown strap from Steinhart.
First of all I need to say that the customer service from Steinhart is absolutely wonderful, the president of the company email me personally to confirm my order and it was smooth, shipping is extremely fast for half a globe traveling distance (Germany --> Australia).
Quality of the straps is immaculate, 5mm thick for the Cognac and 4 - 4.5mm for the dark brown. It is a very stiff leather to wear for the first time but started to soften up after few hours of wearing. It's made from Juchten leather, same leather to make Russian army boot. I really think this strap is made to last.
My other experience with 'nice' strap is when I purchased a strap from 'Strap Culture', different design, more expensive and better packaging. Can Steinhart strap compare with the more expensive strap?? Absolutely!!
I highly recommend this strap for any watches with lug width of 22mm, this is the best value strap for the money, some other company will probably sell this quality of a strap for twice or three times the price, no kidding. If I'm picky, the only improvement to make for the strap will be the keeper, slightly more volume will be perfect.