Battery on the Surface Pro 1 is anywhere from 4 to 6 hours on average for me. You can squeeze out 7 with all wireless off, and using it only for typing. The Pro 2 addresses the battery life. It adds 20% more.

One of the most useful features for me, is the (pen)handwriting recognition on the Pro. I have terrible handwriting, terrible. I take a lot of notes in OneNote, and then convert them to text. This way I can share with my team, all the info I jotted down, in a "professional" manner. A few typos come up, usually upper vs lower case.

The pen is my favorite feature, I use it in Illustrator and Photoshop, daily. Running Ps and Ai, the battery will last about 4ish hours. Not bad, but not great. I usually will hook up an external monitor for Photoshop.

MSoft needs to work on communicating the pen, is not a stylus. It has pressure sensitivity, and lets you rest your hand on the screen while writing. A major difference from the iPad stylus(es).

The pen is amazing in quality. Its a full Wacom pen, with full pressure sensitivity. It counts as a totally separate input, so your "finger" and "pen" are seen completely differently.

In contrast, an iPad stylus thinks that the pen is just another finger. "Write then swipe" simply works on the Surface, for instance.