Depends on if your router supports 2.4 & 5GHz networks too, if it doesn't do 5G then it's a moot point.
Milage may vary on both networks. If you get a good signal in general then it's likely 5G will offer better performance for you because it is both a) capable of faster speeds (2.4GHz is limited to 450mbits if memory serves) and b) 5GHz networks are currently less common so there is less congestion and interference from other 2G networks and devices such as DECT phones, etc which all operate in the same frequency range.
If you can install an app called InSSIDer on your PC or Wifi Analyser on your phone you can see what networks are on each frequency in your area and also hard set the wireless network on the router to any free or less congested channels.
