The only reason I can see for being able to extract more power is if you've been getting knock at tip in. The hydra will let you control the acceleration parameters - ie the enrichment that occurs when you first jump on the throttle, so you can avoid knock.
Example - lets say while driving around with your maf based tuning solution, you realize you get knock at 4350rpm, under the 50% load column. Its not every time, but it does happen. Didn't knock on the dyno at all, and rarely happens on the street, but it does happen. After a week of pulling out your hair, you realize it occurs when you take the car up to 4000rpm gently, and THEN floor it. WAM, knock. So, you have to reduce the timing in that area.
(I've seen this with both ECUTek and UTECs, anything that you can't control the accel parameter on, and you are at the mercy of the stock ECU you might have this issue, ESPECIALLY if you've changed the MAF tube diameter)
That won't happen with the hydra. MAF tubes don't mean anything. It sees boost, and it sees your throttle position. Also, the knock control only pulls a fraction of a degree, or adds just a fraction of fuel when it gets knock. None of the pulling 3-5 degrees of timing, completely hosing you if you're on the track.
This is what a full standalone brings you - full control over parameters that you had no control of before.