Are you asking if it is good to do?
I used to do it, but not as much anymore. I do have a zercher harness which makes them a bit easier IMO.
They shift the weight more to your front, like a front squat, so the abs have to stabilize the weight and core more. They can be somewhat uncomfortable as well, especially for higher reps as it gets tough to breathe and some guys pad the bar to cradle. They are a compound lift, so you are working lots of the body's musculature, like a squat or dead or along those lines.
Will they make you better at other better known lifts? Meh, I dunno!?
They may very well have some carryover. I do think more guys opt for front squats really.
I noticed years and years ago, Louie advocated or mentioned them in WSB stuff, but I am not sure how much they continued doing them to reach some of the high squat and deadlift numbers.
There are quite a few vids of zercher lifts and zercher squats. I think most of the lifts on u tube are zercher squats, sine the lift, popularized by old strongman Ed Zercher, did the lift from the floor, pulling onto the quads like a deadlift, then from there cradling the bar in the elbows then getting up.
Partials can be good if they benefit say a full lift (if that is what one is seeking?) or are being used to get strong thru a certain ROM. Most if not all lifters can do more partially, than full ROM because of leverages.
I think expecting great carryover from doing say partial BP's or 1/4 squats expecting them to fully push your full ROM lift way up, is short sighted. If doing partial deads (from say above my knees) meant my entire ROM got greatly stronger, I would probably never have to do a full ROM lift. But that seems not the case from my experiences.
I was able to pull off the pins nearly #800, but it never got my deadlift higher than #625 or the likes more than other work from below my knees, since that part of my body also needed to be able to handle #700-#800 and could not really.
Also, if one enlists partials in their work, they should be careful to progress slowly, as tendon and ligament strength, can take longer to adapt to heavy loads than muscles.
