Sure, the Wi-Fi performance is worse, and by design. Apart from the initial issues that they have fixed, it specifically has lower EIRP and fewer chains.
I actually don't use the Wi-Fi on my hAP ac2. I have it enabled for worst-case management connections only; but I feed multiple RB962 (hAP ac) into it to serve the premise Wi-Fi.
But the wireless performance is a completely separate topic than the heat.