@vore 

Hi,

You have probably noticed yourself that the Wi-Fi specs of the T3U Plus are superior to those of the T2U Plus. ("AC1300" vs. "AC600")

Both work on Windows 11.

Apart from the above I'd say there are mainly two things to take into consideration.

1) The USB 3.0 ports of some computers have compatibility issues with the USB 3.0 mode of the T3U Plus.
Since the T2U Plus doesn't support USB 3.0 mode to begin with, it won't face these issues. 

2) The "Hotspot" feature of smartphone devices commonly broadcasts its Wi-Fi signal on frequencies that the "EU" versions of TP-Link's USB Wi-Fi adapters can't receive.
So, in case you specifically intend to use the T3U Plus or T2U Plus to connect to the Wi-Fi hotspot of a smartphone (or tablet) and where you live only the "EU" versions of the T3U Plus or T2U Plus are sold, then these are no good for you.
 

Thank you.

If network is 2.4 GHz, will there be faster speeds with T3U ?

Does T3U work if I connect it to USB2.0?

  @vore 

If your Wi-Fi router can handle at least two streams (2x2 MIMO) or more, then the T3U Plus will be faster than the T2U Plus, which is a 1x1 design.

The T3U works fine on an USB 2.0 port.

By the way, the issue I mentioned earlier about the Wi-Fi Hotspot of smartphones not being seen by the "EU" versions of T2U or T3U only applies to the 5 GHz band. There is no such problem when using the 2.4 GHz band.