I recently got a Samsung Galaxy S2 when Amazon sold ALL cell phones for $0.01 and a normal 2-year plan. I opted for tethering capability also, for an add'l $20, and I was surprised to see it work so well. It provides a WiFi umbrella for 2 tablets + one ereader (when I was experimenting and when my neighborhood power went down for an entire night and I had work to get in).
When I checked to see why it was as fast as my very good Comcast connection which gets 20Mbps on the unreliable speed tests, I saw that my WiFi router connections (Netgear N600) show 56MBps. but the cell phone (when neighborhood power is down -- too often) shows H+ and 65Mbps on all the devices connected, with the description "Excellent" and Netflix runs on the satellite devices without artifacts.
I finally realized I must be on 4G, and it does run in San Francisco bay area but I'm across the bay and one of the current maps show it with weaker 4G.
I'm jazzed they're doing this, and this well too.