The only experience I have with wifi cards are the Eye-Fi cards. I'm not sure they're around anymore since they canned their X2 series cards for "being too old" and I think they got a lot of flack for it. Also a lot of cams have built in wifi.

i did like them thou since a lot of cameras had built in menu options for their cards and they had wireless tethering to your smartphone/tablet/computer in that images would auto transfer after being taken. No need to manually go in and transfer it or pick and choose.