Dell Vostro 1200 with Intel(R) Wireless WiFi Link 4965AGN. (Windows XP Pro SP3).
I found it difficult to find authoritative information on a wireless router or access point which would potentially connect with the Intel 4965AGN at (11n) 270-300Mbps.
Intel mention a “Connect with Intel Centrino” logo. It is difficult to find gear which has this logo. Intel simply list a few manufacturers, who do not seem to go out of their way to index their “Connect with Intel Centrino” offerings, but anyway it appears this is a minimum compatibility specification and importantly (unhelpfully) it seems does not imply 11n 5GHz band 40MHz channel functionality, required by the 4965AGN “friendly neighbor assurance” to enable operation over 130-144Mbps!
I found this article: Apple Ups The Performance Ante For 802.11n -- Apple Airport ...
I obtained an Apple Airport Extreme A1143 and connected it in bridge mode to a Linksys WAG325N (NZ Telecom ADSL2+)
Within about 8metres (through 2-3 plaster board internal walls) the A1143 5GHz 11n connection shows 3/5bars & (reported) 300Mbps. But in the next room (13metres) the 5GHz signal does not show up at all, whereas the A1143 2.4GHz 11g signal appears strong (5/5bars) and 54Mbps, and on A1143 2.4GHz 11n the (reported) speed idles at 78Mbps, increasing to 130Mbps dynamically on load.
We have a number of 5GHz (note not 2.4GHz) dual-line cordless handsets in the environment so this may be making the 5GHz spectrum difficult for 11n performance. Notes: the A1143 2.4GHz & 5GHz bands cannot be available simultaneously; the A1143 has internal antennae, and no external antenna connections
Apr 09 (update)
Apple have released (Mar 09) a new version of the A1143 which can broadcast simultaneously on 2.4GHz & 5.0GHz bands. They have also released new firmware 7.4.1 which although on my older A1143 (Gigabyte Ethernet version) does not provide simultaneous dual-band operation, has improved 5.0GHz band distant operation. Now in the room 13metres away referred to above, the 5GHz band 11n signal shows 3-4bars and an idle speed of around 30Mbps, increasing to say 60Mbps on load. The 5GHz default channel has changed from 36 to the higher freq. channel 149. Some users have reported ( see http://discussions.apple.com/thread.jspa?threadID=1930336&tstart=45 ) initial problems after upgrading to 7.4.1 but that was not the case for me.