I happen to have a son of Docs Hickory and he is about 14.2 hands and chunky, although have seen and owned other Docs Hickory that were the larger and lankier type, some easily over 15.1 hands.
While they are wonderful athletes and have a work ethic that don't know quit, they are also a little more the type of horse you need to work with, really don't take to incompetent, careless, inconsiderate handling or riding.
They do best in the hands of professionals and good horsemen to thrive.
Not all have as much cow as you want for any cow work, but the ones that do tend to be over the top cowy.
Thankfully, unlike some other more nervous Doc Bar lines, they are also not as apt to have the OCD behaviors like cribbing, weaving and fence walking problems other such lines may fall into.