My Nexus 7 seems to have poorer Wi-Fi reception than my iPad (1st generation). At home it is always able to reach the router, so not an issue. Occasionally when I am out the iPad will have reception when the Nexus 7 doesn't.
I was looking inside the back cover, and it appears there are a few antenna built into the cover. I am curious if the Wi-Fi antena is in the back cover, and if there is some way I could boost it by attaching an external perhaps.