Does Bosley or Hairclub provide good work? How do they compare in performance and cost?

Many places do good work. Ideally, rather then trust a company, you want to find out who exactly is doing your procedure at the clinic or company.  You should decide based on the particular doctor that will be doing your case that day.  Research the background and experience of that physician. 

I just happened to run across this Q & A from two years ago and felt obligated to set the record straight with regard to the qualifications one should seek in a hair transplant surgeon. It is simply absurd to suggest (see below) that "the doctor [needs to be] board certified by the American Board of Plastic Surgery to ensure they [sic] have the proper training." This does a great disservice to the many outstanding full-time hair transplant surgeons whose original specialty was something other than plastic surgery, who participate in continuing medical education activities, and who, in some cases, are recognized by the American Board of Hair Restoration Surgery. Board certification in plastic surgery is of little reassurance if hair restoration surgery is simply one item on a large menu of cosmetic procedures offered by the surgeon; in these cases, the surgeon and his or her assistants may lack the experience and judgment necessary for achieving excellent results. Bottom line: you can have a poorly performed hair transplant by a board certified plastic surgeon who dabbles in hair transplants with inexperienced staff and who rarely attends educational meetings, and a beautiful result from a urologist or dermatologist or emergency medicine physician and their experienced staff who perform hair transplants full-time.