ANSWER:
Sometimes it becomes necessary to run a dome piston to achieve the desired compression; I believe that’s the only benefit dome pistons provide. Dome pistons can obstruct the flame path and disrupt the squish flow causing larger pockets of unburned fuel during combustion. This can result in engine failure.

I have run grooved heads on engines with dome pistons, the improvement was unbelievable. (see testing results; racemod; 1967 Camaro) Pull the heads off a domed piston engine, groove the heads and reinstall them. With no other changes to the engine the fuel consumption is reduced, idle quality is improved drastically, oil runs clean, engine temperature runs cooler and power levels are up. Initial testing reveled 1/4 mile = 0.3 sec quicker and 4 mph faster. It's no longer necessary to run high ignition advance! Almost too good to be true!