i am yet to test both 2.4 and 5Ghz in detail.

I will report back once i did some bandwidth and stability test.

just did some testing

got weird results though

my router is at my living room.

the signal strength within the line of sight (few meters away) is about -40 dBm

furthest corners away from the router at 2nd floor is about -60 ~ -65 dBm

650MB within line of sight @ 3m25s (2.4G wireless mode N)
650MB within line of sight @ 2m06s (5G wireless mode N)

650MB room at 2nd floor directly above the router @ 2m50s (2.4G wireless mode N)
5G 650MB room at 2nd floor directly above the router @ 1m54s (5G wireless mode N)

the latency is stable for most places in my house (just standard double story house), except for the further corner away from the router.

I have no other comparisons, but It is much better than the router (D-Link L7-N-R2000) that TM provided though. 

It is also much better than vanilla OpenWRT firmware.

there are 2 issues, i've AC enabled on router but the devices I test on don't support AC, secondly the pc that upload the file might be hit a bottleneck due to the hdd and network speed. I need to change my approach  to at least try to maximize the speed of N mode