Got both Harris 9-13” with notched legs & Spartan pro hunt with both stand length legs and 40cm (both non tac legs)
harris
advantages - solid, quick to deploy, always on the rifle when crawling
disadvantages - heavy, in deep heather / long grass legs not long enough sometime., metal can rub through clothing / not comfortable slun on back / shoulder.
spartan pro hunt
advantages - light, long legs over comes deep heather, does not cause snagging when carrying through thick plantations / rubbing on shoulder / back when carried.
disadvantages - but perhaps slightly too tall (with the 40cm) to get a comfortable prone position when sometimes shooting off some flat / hard surfaces. Can be fiddly to clip in before taking a shot, familiarity is key here however if the gillie you are out with takes the rifle and readies it to set up the shot for you, this can cause confusion / faff unless they are familiar with it IME. Not as easy to deploy when crawling into position (i.e. you have to take it off the rifle).
I haven’t experienced the same issue as some on here with the rifle falling over, but the pro hunt model has a ratchet to tighten and stop the rifle rolling.
an alternative, If you want spring-loaded legs that fold down from the rifle, maybe The Valhalla model which can be completely removed like other spartan models or left in situ and the legs folded down- downside is it’s more expensive and heavier!
ultimately I haven’t gone back to the harris as I value the weigh and easy of carrying over the sight increased pain that is deployment of the Spartan. Over 70% of my shots are off sticks; so perhaps not as reliant on bipods as others. I’m sure you could get tolerate either depending on what’s best for you.