On many sites I see people warning strongly against behind the neck pullups. Perhaps these are bodybuilders who might not have flexibility in their shoulders(?). What are the advantages of them over normal wide pullups, or normal width pullups? What are the disadvantages compared to them? Also if they are dangerous for some people is there any way to determine this, e.g. feel for pains etc. I have seen it split pretty much 50/50 saying they are dangerous or not, but few give advantages to doing them. I expect they simply work muscles differently in the shoulder which might otherwise not be hit and so could be a weak point.
I did some properly for the first time and did feel they hit my shoulders & traps differently.