Correct, Enterprise networks generally need the higher number of channels available that is provided with 20mhz width. For example, I have five story buildings

Correct, Enterprise networks generally need the higher number of channels available that is provided with 20mhz width. For example, I have five story buildings with 20-30 APs per floor. There would be too much overlap if I were to use 40/80Mhz channels. Larger channels can be fine at home. But only if you ensure there are no neighbors that overlap with your range. Keep in mind that as you grow in channel width, you'll need a better SNR to maintain those top data rates. The one other issue I can think of is auto-channel on a neighbor's 802.11n router. An 802.11n router might not recognize the 80mhz channel used in your network, and thus pick a channel that overlaps. That being said, I use 40Mhz channels at home with no noticeable issues.