We used the Dryject system for green aerification last Monday. What a great job it did - put a lot of sand into the green and really served to get the oxygen down there.
What amazed me was the fact that the greens were at 90% the following day. Today, only 6 days later, they putted at 99%. Only affect today was the fact that the greens were a LITTLE soft.
I'm just a member and far from an agronomic expert, but this system, to a golfer, really did a wonderful job.