This valve is a stand alone valve of the same type that is in every saginaw power steering box ever made...really any power steering box, rack, etc. So yes, load sensitive. The difference is, instead of little tiny ports like the valve built into a steering gear, these ports are massive. Some where between 5/16 and 3/8" diameter. The "competitor's" spool shown in the image below is the Sweet servo if I'm not mistaken.
And here is a plot for the valve response curves with valve port profiles. My valve is the "55". It has a .210" torsion bar in it. Depending on how it behaves, I may have to size the torsion bar up or down in diameter to tune the steering feel to my liking.
If you want to go deeper in depth, you can look at the Woodward catalog. My valve is the VA955. Tech on pages 3 and 4 of the catalog.
Woodward Catalog
In the event of a blown line or pump failure, I will still have manual steering control. There will be no hydraulic lines going to the box. I've deleted all the hydraulics and welded the saginaw torsion bar assembly solid. I've essentially built a fast ratio manual steering gear and will be packing it full of moly grease like they did back in the day. Came across this nifty site detailing old manual steering gears. Here's a link for those that care.
Old Steering Gear Tech