11-oxo is way more powerful, at least from my experience with it. I ran E-Pharms 11-oxo when it first came out and it was awesome! Leaned out around midsection and it hardened my muscles the F**k up BUT it gave me prostate issues after a little over two weeks of use...
I still plan on running the topical version someday (prototype nutrition) to see if there's a difference.
Lean Xtreme- from what I remember 7-keto isn't hormonal and definitely wont be as suppressive as 500mg of 11-oxo. LX is some good stuff too but it's effects won't be as dramatic.