No, although I must admit they are tempting. However from my reading I understand that the Medallion was designed using PM7A's so they should give a better balanced sound than the PM2A's which I believe can be slightly bright. Also PM7A's should work in the All Fun Horn while the magnets on PM2A's are much too big to fit making the PM7A's a more flexible choice for me in the first instance.
I've recently been given the plans for the Opus One which if I like the Lowther sound would probably be an "end game" speaker for me, and a good long term project. However they really need the PM4A rather than the PM2A otherwise I would have been swayed to try the PM2A's to start with.
My PM2A/Medallions work great.
I was told by Tony Glynn (driving force behind the Lowther Club of America back in 1998, when I got my PM2A/Medallions) and Jennifer Crock of JENA Labs (designer of the Medallion enclosure) the PM2A matches up to the Medallion enclosure.
Over the years, some folks on the Internet questioned the size of the compression chamber in relation to the huge magnet on the PM2A but I am more inclined to go with the recommendation I got from Tony Glynn and Jennifer Crock (who also wired my Medallions up with her JENA Labs wire).
The PM7A is also supposed to work and give outstanding results.