Well another misunderstanding people have about compression is that they think or assume a little gives you a lot in return, and it doesn't. On your engine for example, you may increase yours by 2 full compression points, but it might only give you a 10 HP increase in power on an otherwise stock engine.
Airflow into an engine is very sensitive to abrupt changes in the airstream. Even though sinking a valve by almost an 1/8" may not seem like much to you, it is a huge jump as the head sees it. And it will change the relationship and flow of air as it transitions over the SSR drastically. Porting technology has increases many hundreds of percent since the days of California Bill and others and much has been learned that they didn't even know back then. The closer the valve moves towards the SSR, it makes the radius smaller and hurts the velocity and it restricts the incoming charge in a bad way.
As far as pistons go, dome pistons are available from Ross and others that will raise the compression the correct way, and leave the valve relationship where it needs to stay since you don't have to try to compensate, so you gain on two levels instead of on one and losing on another.
