[awm]

My comments from my (admittedly quick) scan of this structure:

1. The preempt range isn't really an integral part of it, in that you could play wider range preempts. The important part is opening 2M with the 9-10 hcp 6M hands, which we do also and which I think is a good approach.
2. There are a bunch of advantages to this structure, including having two raises to 2M, and retaining the advantages of "having two invites" while getting the GF relays in. If you have as a primary constraint that you want a full GF relay of opener's shape, then these methods look pretty good to me.
3. The methods are also pretty complicated, and you don't really have good options for GF non-relay sequences. If you're happy relaying on all game auctions then this is obviously fine.
4. It will be hard to do a valid comparison of this method with what Sam and I play, because our style is more dependent on judgment and more tuned for the competitive auction.