You asked about pros and cons.
Pros too many to list, I'll stick with the cons.
Cons Finding a reputable teacher with iron palm skills and the right hand medicine then it's TIME TIME and TIME. For iron palm it takes 20 minutes twice a day for at least one solid year (NOT MISSING A DAY, HERE AND THERE) then you may back off to once a day for another year and then you must keep it up or you'll loose what you have. That really doesnt seem like a lot but it is.
Iron vest or body you still must find a reputable teacher that has access to the right medicine and again TIME, TIME and MORE TIME. It takes ONE HOUR AND 20 MINUTES, try that every day for a year or two before you can back off.
There are only a handful of people with real iron palm/body capabilities in the entire world and most of them are old men. No one on this board is capable of real iron palm/body, sure they might have scratched the surface and I'm including myself in this catagory. Wanna argue with me that you are an iron palm master then get yourself some 2" patio blocks, DO NOT BAKE THEM OR SCORE THEM, USE NO SPACERS BETWEEN and DO NOT BE A SISSY AND USE A CLOTH DRAPED OVER THEM...IN OTHER WORDS DO NOT CHEAT. Take them right from where you got them, support them on the ends with building concrete blocks and SLAP through them with an open hand. Anyone can slap through 1, I've seen guys with no training get through 3 blocks, but after you get up to 4 blocks(and that's 8" solid) you got a little training. At 6 blocks i'd say you're on your way to having something that will last, at 8 blocks or more you have REAL IRON PALM.
My point is, in our society today with the hustle and bustle of day to day life even a single guy would find the demands of undertaking such rigoris training programs just too much to complete.
SW
PS: No, I dont want to see any of your youtube videos