iPhone SE is equiped with currently strongest hardware with A9 processing chip, 2GB RAM. More special, camera of it is upgrade to 12MP and it also can record video of 4K high definition. If you are an user who likes recording moments and being prior to quality of image, it is sure that 16GB verision is not for you.
As known, with Full HD video recording mode (1080p), you lose only about 130MB for one –minute short video. But with 4K mode, it consumes 375MB of memory loss. This means with 10-minute video, your iPhone SE will be lost 4GB of internal memory. That is not to mention other contents causing occupation of your memory as images, music, games, application etc...

With high-definition of 12MP will occupy quite much data memory capacity of your iPhone
However, using 16GB capacity is not a completely bad idea. For a group of users who want to save much cost when buying iPhone SE will and they also do not have demand mainly on photography, video recording or games experience, heavy application, the 16GB version is a correct decision. Besides, to save your device’s data memory capacity, you can use cloudy services to save necessary data.