I've been using the ac750 for the last year with 2.4ghz speeds averaging around 104/101mbps. Granted, 5ghz is slower, averaging around 225/96mbps but that's still only around 50% loss compared to 70% loss on the ac1750.
That's crazy, I can get the same speeds, if not better, on my Tp- link ac750 rated at 300 and 433 for 2.4 and 5ghz. 30%of the rated speed is ridiculous.
I recently upgraded my fibre line to 1000/100mbps. I have a Tp-link ac1750 archer c7 with gigabit wifi. My problem is I cannot seem to get anywhere near the speed through wifi. My wired connection gives me 980/97mbps but I only get around 80/90mbps on 2.4ghz and 370/100mbps on 5ghz at best...