However there are a couple of things that do irritate me:
[1] They sniff the header of every web-request looking for desktop browser string. If found they sent you a warning text threatening to cut off your service. It sucks especially when you move to a new home with no immediate internet service and want to tether for a few days.
[2] Non-existent domains redirect to a page with ads (Similar to OpenDNS). Sucks on a mobile since you have to wait for it to load to find out while adding to your data usage.