Look at the impedance rating too, which is arguably more important than the power ratings. 6 ohm speakers can place a lot more demands on an amplifier, which is why it's important to match the impedance of receiver w/ speakers. In general, this means 8 ohm speakers w/ 8 ohm amp.
Since the 110W rating is per channel, you can normally use each speakers power handling rating as a comparable figure. A speaker rated at150W or 275W can handle output from a receiver putting out 110W per channel. Just don't run any system at maximum volume levels. This means keep the teens/kids away from it ;).
Between the above speakers, the 500s will have a lot more bass response than the more entry level 300s IME.
If a receiver that's rated 110w per channel (8 ohms) is paired with a speaker that has a recommended amp power of 20-275w per channel, will it just sound like a smaller speaker that's has a recommended amp power of 20-150w per channel since the receiver can only out 110w per channel?
ie. Will a Onkyo NR709 (110w) paired with a Polk TSi500 (20-275w) sound the same as a Polk TSi300 (20-150w)?
Thanks in advance. An explanation on how receivers and speakers work is a greatly appreciated bonus.