Fi is cool, I used them for about a year.
The only issue with MVNOβs is they get the slowest data (lowest priority) on whomeverβs tower they are using. Even at full speed, often it wonβt be subscription speeds.
On TMo, with Magenta Max, I get unlimited data (truly unlimited) and get speeds in the 800mbps range on 5GUC (Ultra Capacity). On lower signal itβs comparable to AT&Tβs 5G, but without the cap.