I got around 13-17MB/s with my CentrinoN 6230 (BT and 3 band) off my netgear 4500 @ 5GHz. In theory this is a 450Mbps connection. 5GHz is faster but has a reduced range. Same wifi adapter with a Linksys 310N @2.4Ghz caps around 7MB/s, which in theory maxes at 150Mbps connection. Everything affects speeds.. distance to router, system speed, interference, router type, antenna style, atmospheric conditions, file transfer protocol (FTP/AFP/CIFS/NFS) As a general rule, a 450Mbps connection is max 56MB/s up & down, so 28MB/s either direction in optimal conditions. Anywhere between 40-75% of each direction is expected in practice. (11-21MB/s) If you want better, try getting an active signal booster/high gain antenna for the router & laptop. 3dB is double the power. dBi is isotropic, meaning gain obtained from a focused antenna rather than an omnidirectional antenna which broadcasts in 360 degrees.
There is probably a lot of useful information here, but it needs to be distilled into one or two key facts.
Wired doesn't really tell us much other than its not a limit of the hard drive or wire during the wireless test.
Do a wired test connected to your AP lan ports? I would assume that is what you were testing when said connected to switch (switch of AP)
Let me fire up my wifes laptop and do a wireless robocopy. BBL with the results.
But clearly you can rule out your router to the internet, etc .since in your seeing the same speeds not talking through to the internet.
All the wired tests I have been doing so far have been to the Gigabit Switch. The AP also has an in-built switch but I wouldn't expect the greatest of speeds from it. There are 4/5 ports (can't remember off the top of my head), one which is being used as an uplink to the Gigabit switch which uses the only gigabit port that it has, with the rest of ports being fast ethernet (10/100). I will post some results later when I get home (in the office today).