One of the fastest keyboards around is the swype keyboard. The ability to type out full words without having to lift your finger can be both efficient and comfortable. The only thing slowing you down on this keyboard is switching to the secondary keyboard to type numbers. Devices like the Note 5 actually have the keyboard built in to the main keyboard as a top row. You can now have this feature on swype thanks to an Xposed module.
The Swype Row module adds a row of numer keys to your keyboard. This seems to come in handy pretty often for me. The module does require you to be rooted. You will also need to have the xposed framework installed. Then simply install the module. Grab the file from the link below.
via XDA