Linksys Wireless Router :: E4200 Cuts Bandwidth By Nearly Half

I just signed up for Charter's Ultra 100Mbps internet service.  We confirmed it worked at that speed by connecting my Lenovo T520 laptop directly to the Motorola Cable modem.  I acheived just over 102Mbps throughput down.Next, I plugged in the e4200 (v1) router to the modem, and the computer directly to that (wired), and the max performance I could see was right around 52Mbps.  Wireless performance on wireless-n, 5Ghz, maxes out at around 42Mbps.I am concerned about the throughput dropping from 102Mbps to 52Mbps while directly WIRED to the router.  That tells me that the router is definitely capping my throughput. I have turned off QOS, found the optimum MTU of 1468 (used the ping -f -l 1440 [url]...) to find the largest MTU that didn't spit out a fragmented message, and added 28 to that.
 
I am a bit baffled that this top of the line router which some have claimed to see >100Mbps performance over wireless alone, isn't able to achieve any higher than 52Mbps wired. I do have other devices plugged in, but none actively transferring. What could be capping the throughput?  The router worked fine on 25Mbps service, but it seems unable to handle 100Mbps service.