CRAP!  I wrote a long post, but is disappered!
In a nut shell I said that I hadn't heard of Lawton before this board (but this is really the only trans* social web site I am on).  I am wondering if he has done a lot of these surgeries.  I was suggesting that if he has not, I would go with what the majority of busy top surgeons do.  Garramone uses drains, I think that Medalie does too (I think he does a good number of surgeries).  I wonder if Brownstein used drains?  That is how I would make my decision, again, if my surgeon doesn't specialize in this surgery.  I think I would also push to understand why he doesn't have a preference, also.
For me, short term discomfort is meaningless when it comes to outcome.  Do you know how often it is a seroma occurs without drains?  There are probably no academic studies on this.  
Of course, I am 5 months out and still have very small "puff" of swelling under one arm from the drain.  I have never heard of this not going away though.
Hard decision.  Good luck.