Here in Turkey, we still have 3G networks only, those are DC or MC-HSPA+. In April, 4G networks will be active on all networks and we'll be able to use then. Now, it is logical that 4G will use more data with video and audio streaming content, as the bandwidth increases phones can download higher resolution videos etc. and consume more. However, is there a much difference on other traffic? For example, when browsing on same sites with 3G and 4G speeds how much difference you see? Probably may be same for most sites but, some can use image compression technics etc. Also current 3G data prices seem very high here. For example, 1GB data is at least $3. 4GB is between $7 and $13 depending on other tariffs and allowances. There are 15GB plan for $20. I use an unlimited plan with 1GB 7.2Mbit speed and then 96kbit for about $8. For $10 my first 1GB speed won't be obstructed and I can see speeds of 32 Mbit. What is the situation in your countries, how much you pay for your data usage? Are there real unlimited data plans etc? When 4G networks activated, can we see data plans with higher data allowance for the same prices or not?
The four major, national carriers here are Verizon, AT&T, Sprint, and T-Mobile. The pricing wars between those is constant. If you can reach the following site, you can play with the options to see the costs: https://www.whistleout.com/CellPhones
@sis651: 1. Hopefully someone else can comment. It would be difficult for me to comment based on personal : experience because the equipment upgrades I went through simultaneously. 2. For most of your questions, you can get a quicker response by merely searching the web. For example, I typed in Google: "battery consumption on 4G" and got: https://www.quora.com/What-takes-more-battery-life-between-3G-and-4G