router compatible with current network

[live_strong]

it looks like my ISP is going to start usage based billing and i would like to be able to monitor the bandwidth on my end to avoid a surprise in the mail.
my current router (DIR-655) does not have a monitoring feature and is slowly started to die.

i searching around for a new router it looks like the Netgear WNDR3700 might be my best option, but i want to make sure it will not cause any problems with my current setup.

• D-Link DAP-1522 (wireless bridge for TV and Blu-ray player)
• Netgear WGPS606
• D-Link DWA-556 (desktop)
• two laptops (one G, one N)
• one netbook (N)
• DNS-323 (stream video to TV and computer)

one "issue" i have noticed is that the desktop can be sluggish at times when downloading or transferring files to the DNS-323. it is a new computer so i am not sure where the issue lies (card or router). if i use a laptop in the same room i do not notice any problems, so i dont think it is signal related.

i like to think i am knowledgeable when it comes to computers and technology, but i have not been following the networking hardware as close. so i turn to you, the experts-WNDR3700 my best option or is there a better alternative i should be considering?

thanks in advance!