My 2 cents worth..Manual cheaper & better.
I currently have hyd.on my case 590...my last 3 machines..JD690, Case 580 & Ford 420...all had manual thumbs. Which when not in use, I could pull the ..stiff leg out, then with same pin..it would lock nicely outa way.
I also run Cat 320 & Volvo 120 with hyd. & find the thumb never is in right spot.
I actually prefer the ,,Manual thumb.to hyd. From beer cans to wicked large stumps...can lift & move them all. 100% stationary with no movement.I built 2 of them myself, with used steel crops, and few hrs of weldin.My current hyd thumb complete with hyd plumbing and special.valves was close to 3grand , 12 years ago. I really find the relief valve doesn't allow me to work the hyd as hard as the stationary style.I do understand it must , so you dont bent cyclinders.
Good luck on your choices.