Matt
I really don't think there is anyone here among us that can say unequivocally that an amp will or wont work in your situation. Honestly your the only one who can make the final decision. Given what you said about your listening habits I would say you probably don't need an external amp. I don't "need" an external amp in my setup but as time went along I found I really wanted one so I got one.
I don't think anyone here is being snooty. External amplification is a hotbed topic on the internet and we all have our opinions. I try to help as best I can without sticking my neck out too far since the "no amp " crowd can be very defensive.It is best to do lots of reading and make your own decision based on your personal requirements. As for the M80 being 4 ohm , if you look at the impedance graph it spends very little time at 4 ohms and many here drive them without problem with modest receivers .
