The Lift: Push-up slide walks are an upper-body/core finisher that can be tacked on to the end of any upper-body day. It puts the pecs, triceps, and anterior core under constant tension and requires a lot of focus to keep the form in check. If you can complete the movement it gives a great bang-for-your-buck.
The Good: I've been performing a few sets of this movement once a week after an upper-body lift and it is definitely a great way to encourage positional strength and sneak in some core work. I personally include zero direct core training in my own training because 1) it bores me to death and 2) my core strength seems to improve as I move heavy barbells around. All that to say that the first time I did this my abs were very sore for 48 hours after.
The Bad: If you look closely my head drops a bit on a couple reps and I'm not quite strong enough to completely unload the sliding hand. Also, the toe-scurry during the upward movement looks a little silly so if you do this in a big gym you could get some looks.