Linksys Wireless Router :: E4200 Wifi Network - Slow File Transfer Speed

I have recently purchased a Cisco E4200 to replace my D-LINK DIR-655, which I thought was defective because I was getting slow wirless file transfer speed, regardless of setting, location and client.Using the E4200, when I transfer a file from a PC to another, both connected at 300mb on the 2.4ghz band, the file transfer rate reported by windows 7 and networx is from 2MB/s to 3.5MB/s.  I think those transfer rates are not acceptable.  Is that a good assumption ? I would expect something in the range of 10MB/s (which is what I get with a cheap dlink router, wired)
 
I also had great difficulty finding a channel.  I had to try them all one-by-one as the auto channel selection made my PCs connect at 130mb.The E4200 is setup as follows:

-WPA-Personal
-Channel 5
-802.11n only
 
I have tried 3 different computers with different network adapters and they all underperform (IMO..).There are no other wireless networks in my area.I also took the E4200 to my office which is very crowed.  Every single channel is occupied by several wireless networks.  I get a file transfer speed PC to PC of about 2MB.I basically could have kept my DIR-655 as the speeds are identical.