My coworker graciously lent me his brand new Realtek 8188 USB bgn wifi adapter so that I could test throughput at speeds >54Mbps.
WNDR3700-100NAS 01R15 -> 8188 = Link speed of 65 Mbps, ~6 Mbps throughput
TEW-673GRU -> 8188 = Link speed of 65 Mbps, ~49 Mbps throughput
What is interesting to note, the 6 Mbps throughput is what my 673GRU was reporting while bridged to the 3700.I’m hesitant to try flashing my 3700 to DD-WRT as many report radio issues even when flashed back to the Netgear firmware: https://spreadsheets.google.com/pub?key=0As5olSHZWDA7dDhYLTI1WW5HVWxtdUtYdHh5WWhnMUE&hl=de&single=true&gid=0&output=html
I’ve concluded that my Netgear WNDR3700 is no longer suitable, so I purchased another 673GRU. Hopefully the pair of these will perform well otherwise they’ll make gifts for my family members.