I am going to be transplanting the wifi card from my dell to this laptop. I have the Intel ultimate 6300 blah blah blah in that one and after testing both, I agree the atheros card is pretty dodgy.
I get slightly better speeds out of the intel card and I don't get any lag while browsing, etc... And both machines have identical tunings.
I would get an Intel ultimate-N card and call it done.
G75VW-RS72 | 3610QM | 32GB DDR1600 | GTX670M | 2x 240GB OCZ Vertex3 RAID0
Samsung ATIV Smart PC Tablet | Dual Atom CPU | 2GB DDR3 | Win 8 PRO
HP M6 | AMD A10-4600M APU | 16GB DDR1600 | HD7660G | 640GB HD
Google Nexus 7 Tablet 16GB | Droid Bionic w/hacked webtop (full linux)