But at the office we never use a WiFi extender. It's unsupportable and too prone to user complaints.

But first the slow down is well discussed so I will be short on why. In an extender we send a packet twice over the air at the lower speed. This can really hammer the speed in some setups.

I hope you can check out the next 2 links.
Bob

1. http://forums.cnet.com/7723-7585_102-602528.html
2. http://reviews.cnet.com/adapters-nics/trendnet-powerline-500-av2/4505-3380_7-35837407.html?autoplay=true
(we can add a WAP or "router as a WAP" at the other end)