I know nearly as much about strops as I do greek poetry, but it looks a bit narrow?
I'm using a heavy red latigo strap that's 2" wide and another half inch wouldn't hurt. I can't tell precisely from the picture but that doesn't even look 2" wide. As happens I'm cutting a piece of leather that's too heavy to be optimal for strops, mostly as an exercise in conditioning and preparing the leather surface. In the attempts to soften and edge and flatten, hopefully I'll learn something about strop maintainence, and what makes a good one.
So far I find no reason to directly associate a $350 strop with value 10x that of a $35 strop. Disregarding pleasure in use, and measuring only by utility (the quality of the resulting shave and how long it took), I'm hard pressed to say that there's much room to improve above an ordinary 'Good' strop. There's just not that much better to GET.
It would be generous to say you could 'double' the quality of the shave, in your own mind, and silly to say 10 times better. So you do need a USEFUL strop and the tension-able feature appeals to me, but it best be big enough, length and width both. Have you measured the size of your longest stroke? The length if you are using as much room as you please? And the requirements for length and width may vary between razors..
I don't know what options you have available, nor budget. I don't know enough to say much about what constitutes 'Good' quality..
but even a novice knows that size matters.
