This is an incremental upgrade over the OnePlus 3. It improves on the processor and battery life.
Pro Lots of storage (up to 128GB)
Most phones (even expensive, high end phones) only come with 32GB of storage, but the OnePlus 3T starts at 64GB with an option to go up to 128GB. This should be more than enough for most people, even after considering that it doesn't have a SD card slot.