I've had both Apple and Lenovo laptops over the years and both seem to perform similarly on my mixed 2.4GHz and 5GHz network. Lenovo have always been Intel WiFi chips whereas Apple seems to go for other brands such as Broadcom. I find it's the WiFi AP side of the equation that makes the biggest difference and not necessarily the laptop itself. I've gone through different WiFi APs over the years and the differences between the bad ones and the good ones is night and day. The good ones just works with all devices, and ensures each device gets a fair share of traffic. Good ones include Ubiquiti, Ruckus etc. Netgear Orbi has been pretty good too and is my current setup.