I used to have a couple of those P-07 gen 2 stainless steel guide rods from ssguiderods.com, but I ended up selling them. You are right, they are extremely stiff when new, and I also couldn't find the rate published on their website. It only says they are made to factory specification. However, I found they broke in nicely after several hundred rounds.
Although I was happy with their functionality, I got rid of them because I wanted solid guide rods and uncaptured springs for ease of cleaning. I like to be able to toss my guide rods and recoil springs into a pan full of acetone occasionally, and the thread locker holding the screws in for those captured springs probably wouldn't survive that on a regular basis.
One thing you could do, if you like their guide rod assembly but think the spring is too stiff, is remove the spring that came with it, and replace it with a 15 lb recoil spring from CGW. Although I think if you give it a chance to break in you'll probably be happy with it. Just be sure to degrease and loctite that screw if you decide to do that.
By the way, you have a newer model gen 2 P-07 that came with a factory metal guide rod? Both of mine came with the black polymer guide rods and captured springs.