I use a 4G Wifi Modem (BigPond).
And I live basically right on the very very edge of 4g coverage. It switches to DC 3/4 of the time and I am able to ping 58-65 pretty steadily 95% of the time. To sydney qlive servers.
I am having to restart the device a lot of the time to get it to drop back down to 60. Alot of the time i get 75-90 pings, and even 100 asif it was single channel 3g shite again. but with less packet loss.
With adsl 50 meters up the road with bigpond/iinet I was pinging 49-60 anyway with adsl.
Now I am getting 58-70 pretty steadily If I reconnect etc.
As for dl speeds, I'll do one right now;
http://www.speedtest.net/result/1916462339.png
I have gotten 12MBPS down where I am. But have also tested in Hobart CBD and got 52mbps. Worse thing is, it's bascially a heavily beefed up 1800mhz 3G frequency. so its like 3.5g.
1800mhz doesnt travel far which is why the coverage isn't that good. (lower the mhz the further the signal travels).
I pay $59.95 a month for 8gb then capped to 56kbps. (8kb a sec) 49 upfront for the modem. but it has allowed me to play quake again :D