I've been using iperf to test a Lenovo w/4965n chipset against a 1252 on 5 Ghz.
Iperf shows approx 55 mbit/sec and 300 Mbit is indicated as nominal speed on the adapter. I would expect somewhere around the double of that. It doesnt make a difference whether I configure 20 or 40 Mbit channel width on the 1252 and all MCS speeds are enabled. Been over the parameters in the PC adapter and its optimally configured. I'm using Intels latest drivers, 184.108.40.206. Can I configure a greenfield only setting instead of mixed mode?