It is again the Sargent Sniper Rest.
Really depends how you have it set up which one will be the steadiest.
The PSR will be faster and easier to make adjustments with.
The SSR set-up the way my friend and I used it is rock steady, when set up a specific way.
What kind of SP are you using?
Here is me using it.
Sitting Shot with a 308 MOA Maximum - Doe Antelope 350 yards - YouTube
Why the bipod on the front. You can't just use the bog pod with the SSR
With the MOA, it locked everything down supertight
Or is it one of those just buy both and play with it