2-way speaker sizing.

What are people's thoughts about 2-way speaker sizing, assuming they are over an adequate sub. 10", 12", 15", ???



I am moving from a passive 12" tops over 18" subs rig to an active rig. So far I have active 10"s over 18"s, and I like the sound of this setup. What are people's views on the relative strengths/differences of 10/12/15 over subs?



Thanks.

2-way speaker sizing.