I have bought several straps from this vendor on ebay, in my experience the product is exceptional both their leather and rubber straps. I had the straight end previously on a 42mm PO, it is soft and wore very well for over one year and going strong, the white stitch held up well against dirt and other stains, the rubber did get a bit shiny but it maintains easily.
The curved end's are new, so I purchased one for my 45mm PO "SkyFall"... yeah the one that doesn't exist in nature. It installed easily and fits very well the curve is tight to the radius of the lugs and the standoff squares the watch nicely on the wrist. The 45mm watch is much easier to wear with a rubber strap since as it tightens the watch to your wrist and really slims the profile of the watch on it's owner. The texture is a bit of a suede/velveteen finish and only time will tell how well it repels dust and the like, but for now once again I am satisfied with TimePiece Republic and their strap.