MacBook Air WiFi only connects properly to ac router

Hi all,

I have a new 13" MacBook Air (the latest model) with 8GB of RAM. I have a home WiFi network that uses a Linksys E1000 802.11a/b/g/n network running in Wireless N mode.

I have no issues connecting to my wireless network with my old 2008 White MacBook. My Transmit Rate when I'm connected is consistently between 117 and 130 Mbps. However, my new MacBook Air only connects at a Transmit Rate of between 5 and 50 Mbps. This strikes me as very odd and it does show a significant decline in my ability to access the internet at normal speeds.

I took the Air to a local Apple Authorized service center with a "specialist" tag, so Apple prefers them. Their tech gave me my Air back saying it "Passed all diagnostic tests" and that was the end of it. He told me he tested the WiFi on the Air and couldn't find any issues at all. However, he did say he was testing on a wireless router/AP that was 802.11ac. Now, he also told me that if I connected to a router that was 802.11n I wouldn't have any issues at all.

But this is not the case.

My issue is entirely reproducable and my Air always connects at sub-par speeds in my house. I've tried everything you can imagine and Apple Care can imagine with regards to tweaking and testing my router and my Air. No problems can be found. My only conclusion is that there is some issue with my Air's wireless card that does not allow it to connect properly to a 802.11g/n network. I tested this by setting my router to 802.11n only and 802.11g only. My old MacBook connects at the highest rate it can (always) and my Air connects at around 5 most of the time.

I have not had a chance to test the Air on another router, but I'm going to tomorrow. I don't know if I have access to an 802.11ac router, but I"m going to ask around. My question to the community is this:

If Apple Care phone support can't find anything wrong with my setup or my Air's software and I can't seem to get it to connect to any router at normal speeds: do I not have a case to get something done from a hardware perspective?

Does anyone else have an issue with the new Air's running at sub-par speeds like this?

P.S. I do not have any other issues with my Air. I also do not experience disconnects and reconnects with WiFi. I just can't get it to connect at higher than 5 Mbps most of the time.