5GHz wifi doesn't necessarily mean extreme speeds. It'll depend on the wireless hardware on both the router end and the specific wireless card your device has. Most routers will advertise a max wireless speed but it's typically the combined speed for all antennas rather than the specific speed for one device. If you are seeing the same wireless speeds on both the T3200M as well as the mesh network then the issue isn't related to one router and may be with the wireless device you are using.
What specific wireless device are you testing the speed with? (Make/model/year) Does the wireless chipset in it support 802.11ac or just 802.11n?
hi there jgg123
Wireless speeds is also dependent on signal noise that might exist in your neighborhood; the more clustered houses are the worse the results.
I would test first using a hardwired connection (using ethernet network cables). the most reliable test happens through iperf v3 and not your usual flash web browser app.
note: your network test also is limited on the capacity of the server on the other side to meet the speeds.