My highest download speed is 38 MB/s. I got it in memphis back before 4G was officially turned on.
Now in most 4G areas in the south, I get around 5-12MB/s, sometimes more. 5MB/s is more than enough for anything I want to do while traveling.
Also, I noticed that in some areas, I'm getting up to 1.2MB/s over 3G, while people with 3G smartphones with me only get 400-500kb/s in the same location on the same network. Makes me wonder if 4G phones get better 3G reception.