Ok, I'm ready to report in.
I received my 15" Retina MacBook Pro with 8GB Ram, 2.3 i7 CPU, 256 SSD drive and Lion 10.7.4.
First order of business was to get a final backup my stuff off the former 13" MBP and prepare it for movin' over.
I wiped Lion off of the rMBP and did a fresh install of Mountain Lion 10.8. Took all of 8 minutes. After some disc to .dmg file creations, I installed my Logic 9 on the rMBP and it wouldn't open. Duh!, it was the 9.03 disc image. Once I did the Software Update and got the 9.1.7 patch, it opened....and whoa, did it open quickly. Since I don't know enough about the plug-ins, etc, I don't have anything to report on that. In running my music projects(I run in 64-bit), nothing crashes, nothing overwhelms the computer and shuts down. It simply works....and works like a bolt of lightning.
The 15" screen real estate is nice, but Logic really sped up tremendously on this SSD drive. I shelved Logic for a while because GarageBand did alot of the basics that Logic seems to require multiple steps on. With the improvement in speed in LS9 and the improved screenage, I'm ready to dust off my Logic Pro Training Manual and start diggin in some more. I really think the author of that manual is a cool guy.
As far as Mountain Lion itself, there are a few annoyances that I hope 10.8.1 will address, but the speed on the Retina MBP across the board is something I only dreamed about before. Can't wait for the Logic Retina Display update since it will prolly come before Logic X.