Like Keith says, more important than whether you have 3G, 4G, or LTE is:
""How much spectrum has the carrier licensed in my city, and how much is allocated to this kind of modulation?
How many other people am I sharing the local tower with? In other words, how big is my cell, and how many towers has the carrier built or contracted with?
How much throughput are my cellmates trying to consume?
How much throughput has the carrier built in its back-end network connecting to the tower?
You might notice that all of these meat-and-potatoes factors involve the carrier spending money, and they all involve gradual improvement in behind-the-scenes infrastructure that's hard to get customers excited. Persuading you to buy a new cell phone with a sophisticated modem and sign up for a two-year contract is a different story. So they don't sell you something measurable where they could be held accountable; they sell how sweet it feels to be using a sophisticated radio modem protocol to talk to them.
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If the carrier sold you "384 kbps Internet access anywhere in the coverage area, outdoors," that would be something you could hold them accountable for. The carrier might even have to put a brake on signing up new customers until it could build new towers or license more spectrum for everybody to share, if it made that guarantee.""