Some people are still upgrading from 3G smartphones to 4G LTE smartphones. Invariably they are surprised to see the data use increase. You should plan ahead and expect your data to increase 2 to 2.5 times at least, just doing the same things. Based on increasing speeds, expect this increase data use to continue. The expectation is average cell phone will be using 5.5 GB per phone.
This is attributed to the fact that we can do more faster and in shorter spans of time correct? Afterall, a 1GB file on 3G is still 1GB on LTE, but with the ability to stream higher quality media on LTE, it stands to reason that we would consume more data rather than if we were trying to view quality content on 3G and giving up 5 min into the buffer time.
This would happen for several reasons:
1) As you mentioned, more of the page and any media associated with that page will load even if you only spend a short time on the web page before moving to the next. Since it loads faster, you also get to view more pages per unit time than before. 2 reasons there that increase data.
2) Media streaming - Also 2 reasons that increase data use. First, the media will buffer faster. If you start watching a video and in 10 seconds determine it is boring and leave. With 3G you may be barely ahead of the 10 seconds, whereas with LTE, the entire 5 minute clip could have already buffered into memory. Second, especially when delivery video, but also applies to music, the speed of the connection will trigger which resolution to request for streaming. On 3G you will likely just get standard definition video. On LTE, you will get High Def video which consumes 4 or more times the data rate of standard definition.
3) Updated Apps - As apps expect to have a faster connection they are being programmed to consume more data to give the user a better experience. The Facebook app is a good example. All the media on the page started to be preloaded for your convenience, at a cost of a huge uptake in data use.
4) Since the speed is very similar to what you would get on a home Internet connection with LTE, you will be more likely to use it for hotspot use where doing this on 3G would have been painful and reserved for times you absolutely needed something
Therefore you can "do the same things" but use a tremendous amount of data doing them once you get faster connections.