Pro Included Stylus
The stylus that is included ins't a regular passive stylus. It can detect hundreds of levels of pressure, and has active palm rejection software (when it senses the tip is close to the screen it will ignore all touches). The back of the pen acts as an eraser as well.
Pro Good performance
The i5, 4GB of RAM model of the Surface Pro 4 performs well, although it isn't meant for gaming or extreme performance tasks (there is a i7 model with 8GB of RAM, however that costs $1600). The $999 model scores a respectable 6436 in GeekBench 3. For regular tasks such as multitasking Chrome and Microsoft Office, the Surface Pro 4 will feed very quick, although heavy programs such as AutoCAD 3D will run slow.
In terms of gaming, it can handle 2013 titles (Tomb Raider and BioShock Infinite) on medium settings at 30-40FPS
Pro Excellent keyboard & trackpad
The keyboard is similar to what is found in many high end ultrabooks. This is unlike any older Surface keyboard - it is much improved.
The trackpad is one of the best available on a Windows machine. Gestures register with no problems, and the track pad is a decent size this time around as well.