Good signal strength, problems with 5GHz

This wireless USB adapter ASUS has been the key that is most wireless networks around me and with the best signal strength.
The drivers are unfortunately insufficient, there is little adjustment options and the installation in general seems to be flawed because in the registry, an entry is added, which is to load an extension that does not mitliefert the driver.
It is a service installed, the well intended to maintain the USB switch, but slows down the change from 5 GHz to 2.4 GHz band and vice versa. The best I go when I install only the driver without the other utilities.
In the 5 GHz band, there are problems. My adapter is approximately 5 meters from the router away through a concrete wall. The signal strength is excellent, and the throughput is> 585 Mbits. The problem is that the connection high packet loss has. So it happens from time to time for short loss of connection in online games. Pinging the Router can take up to 5ms, which is too high in the local network. I have several solutions by, have the router tested and conclusion is that the problem only occurs with this WLAN stick. My NetgearWDN3100v2 receives the signal only sufficient but the connection is still stable in the 5 GHz band.
I am therefore not sure if I should return the adapter, in the 2.4Ghz range everything is top. For the price I would have expected a more functional operation in all frequencies.

Update:
Did the stick now returned and exchanged for an AC USB 2.0 Stick from Netgear. The reception quality is there a little weaker, the uplink speed, however, higher. But above all, the stability of the connection is top and the latency to normal values. So I either had bad luck with a defective ASUS stick or there are general problems with drivers or hardware.
(The energy-saving function for example can be the ASUS not leave because no adjustment for the driver exists. But this should not be a reason for my problems, since alternative adapter itself with PowerSave work reliably)