For me, I just like wired ethernet better. Overall, simpler to configure, use, secure, and manage, and you can't beat gigabit links for bandwidth/$. I have 802.11n, but pretty much all it does is allow the laptops, tablets, and phones onto the network. The MythTV frontends, desktop machines, and home automation/telemetry bits are all hard-wired. I also keep all my data on a central fileserver in the basement, so having gigabit links from the desktop machines (and laptops when I plug them in) really makes working with large datasets significantly faster.
As for my setup, it's really rather unimpressive from any datacenter standpoint.
- Wireless AP (802.11n) and NAT box (TP Link WDR4300 running OpenWRT)
- Cable modem
- Managed 24-port gigabit switch (serves 3rd and 2nd floor ports, dual fiber links to downstairs switch)
- Managed 24-port gigabit switch (serves basement, and 1st floor ports, dual fiber links to upstairs switch, dual fiber to backup fileserver in detached garage)
- House fileserver
- MythTV/home automation/voip/webserver box
- Tuners (HDHomeRun and DirecTV gear + HD-PVRs),
- ISY-99 Insteon gateway