4 hours should not be your deciding factor mate. You should be picking the best surgeon for you. If you are leaning towards him based on geographical location, and have not yet consulted with the top guys, then I am afraid you are still not ready. Each surgeon will offer up different plans, different estimated number of grafts, and differing opinions on your lifetime donor supply. You need to know how many grafts you need, and what the placement plan is, i.e. are you going for dense packing in a small area, coverage over a wider area, hairline work, crown work? Also, can the procedure be performed in a single session or multiple smaller sessions over a few years? Are you getting strip or FUE? Bottom line, are you picking Cooley because you liked his long-term plan for you the best? Just an example, Hasson & Wong prefer to perform much larger surgeries in one pass for in excess of 4,000 grafts so you don't have to return for a 2nd procedure until the future, whilst other surgeons like Dorin and Wesley may prefer to offer a smaller procedure for 2,000 odd grafts with the plan that you return for a 2nd procedure in a year to add density. Pros and cons to both, but have you thought that through?