Have a user with a Lenovo T61 laptop, controlling its no-longer-actively supported Intel 4965AGN WiFi adapter chipset. With the pretty much latest 15.3.1.0 (Intel ProSet Wireless/WiFi) client software running under Windows 7. They at times wirelessly connect with a Merlin-firmware RT-AC66U router that is shouting at the adapter from about 2 meters away, "historically" at a 72mbps link rate on the 5 gigahertz band. Which (1) had seemed like a tad slow link rate and (2) occasionally reported slightly-drifting-up-and-down other link rates.
Upgraded the RT-AC66U router yesterday to Merlin version ...374.41, and suddenly the laptop connects to the 5 gigahertz wireless LAN at a solid (non-varying) 144 megabits per second.
The now-extremely-happy-camper user also pointed out an old Intel product brief:
http://www.intel.com/content/www/us/en/wireless-network/next-gen-wireless-n-brief.html
referring to the 4965AGN chipset, apparently written at a time when the "N" specification was only in draft stage. The brief describes the chipset as hopefully having a potential for a 300 megabits per second link rate:
"
Up to 2X greater range and up to 5X better performance with optional Intel® Next-Gen Wireless N technology enabled by 2x3 Draft N implementations with 2 spatial streams."
Perhaps due to the latest Merlin change from previously-not-as-compatible RT-AC66U wireless drivers, the user at this point feels like their version 374.41 glass is doubly full at 5 gigahertz, rather than half empty.