Your increased polyp extension is probably due to the explosion of particles available for them to eat - the majority of which had likely accumulated in dead spots and has now been stirred into water column. Same goes for anything you put in the tank now, such as food, which will stay in the water colum longer as well. This may also lead to more making its way to your skimmer, so you might see an increase in skimmate as well.
That being said, I run two Vortechs MP40s and 700gph through 2 seprate 3/4" return lines in my 100g. At full power the flow is ridiculous and I will either blow sand or splash water out of my rimless tank. In areas where I have found the flow too high, my acros will only branch along the direction of the flow, which looks strange and very un-natural. Some fish also don't like too excessive of flow and small/juvenile fish can be easily over-whelmed.
Getting new toys are fun. Enjoy your new powerheads.