Smee - I had preventative surgery at the same time as when I had my affected breast removed. I knew I wanted it done the moment I had my diagnosis, and I knew I wanted it done ASAP as well rather than waiting.
I would say there are Pros and Cons.
Cons. Well, I can't say I like the look. But then I've barely ever looked at it and I am committed to reconstruction so it's a temporary thing anyway. Also at the time it was psychologically a very big thing to deal with. Obviously for you opting to go for it at the same time as reconstruction then you would not really have these issues to contend with. I obviously can't comment on whether taking the mastectomy with immediate reconstruction affects recovery rate, but maybe someone else on here can.
Pros. Well, the relief of not having to worry about recurrence on that side or a new cancer kick starting itself there is immense. I see the worried threads on here and on BCC forums when women are facing their annual mammogram and as I'm prone to be a worrier I'm relieved that that's not me. Also, surgically it means it is easier for the surgeon to make a matching pair when it comes to reconstruction.
I thought it would take some effort on my part to get my surgeon to do a preventative mastectomy, particularly as (as far as we know right now) this was an opportunistic cancer, not a hereditary one. I worked out my speech in favour of it and delivered it off pat, expecting some debate on the matter as surgeons can be reluctant to submit patients to unnecessary surgery. Instead he sat bolt upright from his surgeon's laconic and unflappable slouch in his chair and said to me "Interesting. That's what most female doctors or doctors' wives would do". As far as I was concerned that was the best reason there is for doing it.
I admit I'm biased on the subject so do bear in mind that I never felt I had much affinity with my breasts. They never made me my fortune and one of the blighters tried to kill me! Joking aside, at the time they weren't something that I felt were intrinsic to my femininity. I must admit that the de-feminising that occurs through treatment has made me reconsider my views on this and if I can have reconstruction I will definitely go for it. I'm rather obsessed with boobs these days and catch myself staring enviously at a decent cleavage! I'll get myself slapped one day at this rate.
WRT to reconstruction, obviously I don't know what size you are naturally but initial forays into it have suggested that if you've had radiation on the affected side then it's difficult for them to go much larger than a C cup (luckily for me I was only a B and have no desire to go bigger than what I was) as your ribs are more brittle and can't take the strain or summat like that. I could be wrong though. A fellow patient told me that.
I hope this helps. Although the amount I've rambled on about it I've more than likely confused rather than clarified.