Hair implants - info please on pros and cons, facts.?

My hubbie is 66 and is very self conscious of his thinning hair. He is not vain in any other area but in this one, it really bothers him. We were discussing hair implants - do they really work, how long do they take, does the hair stay, on and on. My question is directed to someone who has actually had the implants personally or knows someone close that has had them - all the pros and cons - and also, what do they usually cost. Thanks!
I want him to be happy and if these would work, I would do whatever it took to have it done for him.