iPad 3 with iOS 6.1.3, slow wifi

I have an iPad 3 (the invisible one that disappeared when the iPad 4 came out *smile*) that's been updated to iOS 6.1.3. I can connect to WiFi fine, both 2.4 and 5GHz. However, when I run "speedtest.net", which used to run just slightly less than our download speed (currently about 16Mb/s), it is now running about 1/2 of our download speed or less. Tried the iPad right near the router, and no change in WiFi speed. Rebooting my router and the iPad has no effect. I am using the same router and router settings as when the iPad WiFi speed was fine.

All the other wireless devices that I have are fine, including my Android phone that shows speedtest.net runing at about 16Mb/s.

First serious thing I tried was resetting the networking on my iPad...this had no effect on the slowness problem. So I tried a restore install, and that has had no effect on the slowness of the WiFi.

I can live with it the way that it is, but it really bothers me that the iPad is so much slower than it was with previous versions of iOS.

Any suggestions about how I might debug this, or is this typical of iOS 6.1.3.