I rotated at NMCP and NMCSD in ortho this fall. Both rotations were excellent, but NMCP ended up being by my favorite of the 2 programs... didactics were more structured and the volume seemed higher. With that said, I ranked deferment as my first choice and was granted a full deferment. I agree with backrow's post about the Navy transitioning to straight through training...was told multiple times at both facilities that this was the trend (madated by the RRC) although it was going to take some time for that to fully occur. The Navy now only takes the number of interns in ortho they have gme 2+ slots for... ie 11.
As far as the deferment goes... I can only say what I did. (I would have been very happy training with the Navy, but deferment was the best option for me.) In mid summer, we were informed there were app. 40 people wanting to do ortho with 11 Navy slots and an anticipated 10 deferments (which increased to 12). I did 2 Navy aways and worked hard at both. My rotation at NMCP has been my best one of 4th year... great people... great experience. At all my Navy interviews I informed them that I was most likely going to be ranking full deferment first although I would be happy to train Navy. I also sat down with my attendings and talked about pros and cons of each route, got letters of rec from each and included them in my GME1 packet. A week before selection board, I also contacted the PD's and Specialty leader one last time to notify them of my final rank list. The last thing I did was email my list of civilian interview offers for inclusion in my packet.
I've read posts on here about doing aways... not doing aways... getting noticed... not getting noticed...etc. I think it's important to be known to the Navy programs since you need the support of the PD's in order to get a deferment. As with any away.. work hard and do a good job. If they had decided to pick me up for Navy GME and not grant the deferment, I would have been very happy, since it would have been an ortho slot (win-win situation in my book.) By working hard I ended up with good letters that I've used for my civilian application and those letters get mentioned at every interview. Another important thing is to be competitive in the civilian match. I'm guessing the more interview offers you have from quality programs by the time selection board rolls around... the better your odds are.
Hope this helps.