I would say the benefit of more(quality) watts would be headroom. Some specifics like how loud you listen and how large/small your room is should determine if you "need" more watts than 80/100 watts.
I have a Yamaha A-S1000 integrated amp with "only" 90w/ch and let me tell you it is the most potent 90w/ch I have ever heard/owned. This thing is a beast at 48.5 pounds and it does not even break a sweat driving my Klipsch RB-75's(97dB) at ear bleeding levels in my 5000ft3 room. I know the 75's are bookshelf speakers instead of full range but they do bottom out in the mid 40Hz region.
Bill
I have a Yamaha A-S1000 integrated amp with "only" 90w/ch and let me tell you it is the most potent 90w/ch I have ever heard/owned. This thing is a beast at 48.5 pounds and it does not even break a sweat driving my Klipsch RB-75's(97dB) at ear bleeding levels in my 5000ft3 room. I know the 75's are bookshelf speakers instead of full range but they do bottom out in the mid 40Hz region.
Bill