Let me be the first to say Congrats and to remove any liability(just in case).
I joke.
If hadn't just bought a second house I (probably)would have agreed to the upgrade as well.
The offer is very tempting even now(I'm broke).
Any way... nobody ever answered my question about the M100's being designated left and right.
I know a tower (center, probably M80) is in my future.
I look forward to hearing your thoughts about your new towers.
Again, congrats.