Yes, split screen is quite fabulous, and a great way to avoid the somewhat messy management of re-sizeable floating-windows on-
screen when displaying content.

I like the way that surface implements the feature for opening apps, but dislike a few aspects of the implementation. First, the proportions of the split screen are built-in: so for example, the main window is 3/4 of the screen, and the split is 1/4 (please note, these are not actual dimensions). Second, when interacting with the smaller screen, it automatically expands. This would be annoying if you just needed a small sliver for a calculator, but wanted to keep the larger screen open for reference. It would also be nice to have the option to split the screen again vertically (eg. 3-pane arrangement).

I'm not sure if, via some setting, the above can be changed, or if the implementation has been updated since I last saw it.

I generally like the way that Samsung has implemented the feature, though think that it can still be improved upon. Still, either implementation are welcome as the underlying hardware running these devices becomes more and more powerful, and the app selection continues to mature!