My operation was 6 hours (I had already had a left vertical skin sparing mastectomy 12 months earlier) and I went from a DD to a D....things fit that little bit better which is nice.
And, in answer to your question, yes I do think it was all worth it. I love the result, I love the softness and warmth of my breast and (after having had an expander inserted as part of the mastectomy op) I hated the hardness of it and how it sat so high on my pectoral muscle. The new breast looks identical to its twin...and a bonus is I can wear off the shoulder tops and no bra (if ever I feel brave enough). :)