Test situation: NAS - Router - 15m and two concrete walls - WLAN stick, WLAN N, 2.4GHz, 40MHz bandwidth.
Results:
The Linksys AE3000 has the highest rate of up to 13 megabytes / sec for large contiguous video files! When copying of individual small files (5MB per file), the maximum speed reduced to 8.5 MB / sec (megabytes always!).
The Netgear N900 WNDA4100 closely follows the Linksys with a maximum of 11.2 MB / sec for large files and 9.4 MB / sec for small individual files.
Asus USB-N53 N600 delivers up to 9 MB / sec, but not always. The rates vary somewhat here. I think 6-8MB / sec are realistic.
Hama MIMO WLAN USB2.0 adapter is very similar to Asus, but a little bit slower. Under good conditions, it also provides 8MB / sec.
TP-Link TL-WN823N Mini Wireless N USB Adapter is the slowest with a maximum of 6.5 MB / sec.
The sensitivity of the WLAN sticks (signal strength at the Stick) correlated roughly with the maximum transmission speed. However, I think the Linsys and the Netgear here for almost identical.
It should be noted that the Linksys AE3000 and the Netgear N900 WNDA4100 a corresponding router presuppose that can also supply the required 450Mbit. On a 300Mbit router is two sticks the maximum transfer rate on par with the Asus - here, therefore, is not worth the extra cost.
One more note: The Netgear, Linksys and Asus may either the 2.4 or emfpangen the 5 GHz band. Here the product description is sometimes somewhat incomprehensible. Simultaneous reception is not possible in my opinion.
The Einreichtung all sticks I've always done that at first the appropriate drivers have been downloaded and installed from the manufacturer's website. Only then I have the WLAN stick connected to the PC. Win7 64bit running smoothly with all sticks.