Well that was fast, Samsung sold 150,000 units of the Galaxy S IV LTE-A in Korea, which is also home for the manufacturer. After selling 20 million units of the Galaxy S IV worldwide, the LTE Advanced version of Samsung's flagship seems to be doing pretty well, even if some Koreans are angry because Samsung announced that they were making an LTE Advanced version after they had purchased the original version. They're probably right to be upset, and maybe even Samsung should make up for the people who purchased it within a week of the announcement, however, people should know better by now, we already know how Samsung works by now. Anyway, 150,000 units might not sound like a lot, but it's all from a single country, in just 2 weeks, so the expectation is pretty high for the device to sell well. Samsung is the pride of South Korea, being the international giant that it is, so it's expected for a device specially made for that market to sell big.
The Samsung Galaxy S IV LTE-A is only available in Korea and it's even better than the international version with a Qualcomm Snapdragon 800 processor clocked at 2.3 GHz inside instead of the 600 the rest of the world enjoys. The rest of the device is the same, 5 inch Full HD Super AMOLED display, 2 GB of RAM, 13 megapixel rear camera and a 2.1 megapixel front facing camera, both with 1080p recording capabilities.
There are no differences on the software side as well, Android 4.2.2 Jelly Bean with Samsung's TouchWiz 2.0 (a.k.a Nature UX) on top of it. Among the mountain of features the GS4 has, you'll find all the Smart features: Smart Stay, Smart Pause, Smart Scroll and Smart Pause. Also you get Air Gestures, S-Health, S-Voice and S-Translator, just to name a few.
Samsung didn't say anything about the LTE-A version to be available outside Korea, but my guess is that Samsung is going to try to hit every market possible, so if you live in an LTE Advanced area, Samsung is probably looking at you as a possible buyer.