Here is my version of the saw bench made by Kari Hultman and Dan Klauder that I posted about previously:
I had a large alder sawed up several years ago and every board is streaked like this from minerals in the soil.
It takes almost no time to make this bench and, so far, seems to be a very good design. Ripping down the slot in the middle is very satisfactory. I made this bench just a little bit taller than my old one and it is an improvement. With my upper leg straight and my knee on the board, my other heel is just off the floor, so most of my weight is on the knee. It lets me take a full stroke. A matter of personal preference and yours may differ.
Concerns were expressed about stability, but so far it doesn't seem to be an issue because your leg acts as an outrigger. However, it occurred to me that it would be very easy to slant the bench legs outward without impairing the bench's functionality and you could also make the legs trapezoids if you wanted more lateral stability. Neither of these enhancements would add much to construction complexity.
I have a more traditional saw bench, so I'm going back and forth to compare them.