Orbi RBR750 wifi speed

A couple thoughts. 

1. Why do you want faster speeds on a mobile device? 4k streaming only takes 25-50mbps.
2. The 752 system wasn't the fastest system. It was a base model with dedicated backhaul (wireless connection between router---satellite). Its 5ghz fronthaul was only 1200mbps with a 2x2 antenna configuration. Most test that I seen testing during performance reviews were in that 500-600mbps range. And with only a 2x2 5ghz connection, it left some performance on the table. 
3. What modem is it connected to? 
4. what speeds do a wired device see? Wireless is hard to judge as many things impact performance. Such as distance, interference from other signals, network congestiong, etc. So while its nice for a baseline, it isn't the best way to test.