5Ghz does not mean that the quality at end of the day is better.
Biggest disadvantage of 5Ghz in contrast to 2,4Ghz WLAN is the range.
Got the same "problem" in my room. For me 2,4Ghz has a much better speed since the Signal of 2,4Ghz is much better.
Another problem, at least in Germany (do not know how other countries handle it) is, that 5Ghz frequency is also used by radar (e.g. air traffic control, military). Since these services have a primary use of channel 50-140 it can happen, that the router has to change the channel to 36 to 48. Usually you should not notice any disconnect while that happens. Nevertheless I already got some disconnects due to the "DFE wait time".
At the end LAN is better than WLAN. Also for gaming. If there is not a chance to use a LAN Cable I would try DLAN before moving to WLAN.