Hereís my 2 cents on this:
When I started customizing my racquet a few months ago, I had never heard of this MgR/I, or any other magical formula. I started modifying the racquet through trial and error, based on what felt right for my game.
I started with a 300g (strung) racquet. After OG and dampener, 312g.
I started adding lead at 9 and 3, which reduced twisting considerably and increased the swingweight. Then I added a little lead at 12, for more swingweight. Then it felt too headĖheavy, so I added 15g of silicone in the handle.
At this point, my racquet feels great for my forehand. I am still struggling a little with my 1hbh, but I think it is just a matter of getting used to the new balance, after adding silicone in the handle.
The current specs: 350g, 4.5pHL, 350SW
Hereís the fun part.
A couple of weeks ago I stumbled upon this thread.
So out of curiosity, I checked my numbers and the results are:
MgR/I = 20.7
MR^2 = 378
Thatís pretty close to travlerajmís ideal numbers.
I really donít think this is just a coincidence. Physics donít lie, you just have to know the formulas and how to apply them to real-world situations.
I must also add that I play with an Eastern grip and hit fairly flat, with a long swing.
I believe that these specs are better suited for this style.
Wilson BLX ProStaff 90: 368g, 7pHL, SW=352. (Wilson NXT 49lb / Lux AluPower 45lb).