We have two (2012 models) P6R's, after trying several over the last year or so.
If you're serious about getting one, try riding some demo models, focusing on which bars you like, as well as gearing.
We both prefer P bars because of the various hand position changes, but be warned that if you have huge pillow hands you might find the grip area a bit too narrow. Knocking the left shift lever up can be an issue in this case. As well, one thing we like is that they feel faster/sportier at the lower hand position.
P bar Bromptons also fold a little bigger, making it a very tight squeeze into the B&W hard cases, if air travel is on your horizon.
Right or wrong, someone will chime in (hopefully)