I use several, depending on the gun and type of shooting I'm doing at the moment.
Model 25C series S, 13.5" - 27" for sitting positions when I dont have my shooting sticks.
Between the sticks and bipod, I feel the sticks are quicker, quieter and easier to manuver when a coyote is coming in to the call and looking for movement. The bipod is steadier, and on something like a deer in a field, I'd rather have the steadiness of the tall bipod.
I really like the Model S-LM, and S-BRM (9-13 swivel and 6-9 swivel, both with spring ejection leg notches) for adjusting elevation when already lying prone behind the rifle. Easier for me to adjust one handed with spring ejection, rather than trying to pull the leg out and then turn the knob to tighten it all with just one hand while the other hand is supporting my weight and tilting the rifle from side to side.
I also have the above models with the standard friction locks. They are fine too, and easy enough to use when I am above the rifle and have both hands free to adjust the leg lenghts, but if I am in a hurry; the spring ejection is faster for me.
I see what Broz is saying about the bottom portion of the spring loaded ones being pre loaded. Fortunately for me, my belly is big enough that I never end up using the lowest setting when prone, LOL
If I shoot with a bipod from the bench, the BR swivel works just fine, regular friction lock is fine too, because there's no hurry and both hands are free.
I like the pod locks for eliminating some of the recoil induced torque, but they take up additional space behind the bipod and when carrying the rifle on a sling, sometimes they dig into my shoulder. I know a guy that machines smaller ones, I might ask him make me a couple of them.
For my body size, I didn't find the model H or the model 25 tall enough for sitting positions on coyote stands. If I called facing up hill, or on perfectly flat ground perhaps they'd be ok, but I usually sit on somewhat of a slope looking down hill.
Additionally, sometimes the 6-9 isn't tall enough and other times the 9-13 is too tall. Shawn Carlocks video mentions that he carries both. If Harris or somebody would come out with a 6-13 or similar, I think that would fit the bill for nearly any prone shooting I would ever encounter.
Well, there's my 2 cents, even if it took a dollars worth of space to say it