I agree. When I bought my SP3 I was considering waiting on the Y3P instead, but when I heard they were going to drop the ball and leave out the stylus (once again) I decided to abandon Lenovo once and for all. Yes I know they want to force me into their more pricey Thinkpad lineup, but that only comes with a 1080p screen.
Agree with you concerning the battery, but the idea of a projector is excellent. And if they push it, i.e. good resolution + battery life, it could become a major plus for a tablet. I mean, watching Breaking Bad again in my bed and displaying the movie on my ceiling would definitely charm me.
Concerning Android, the real problem is all the shit they put over it. Because if you take a clean Android, such as the one in every Nexus device, it's in my opinion the best OS for a mobile device.
One important thing for me coming from a mac, track pad control! I have recently owned the yoga pro 2 and the sp3 at the same time. Without a doubt the sp3's track pad is smooth and precise. I also zoom a lot in internet explorer and zooming in IE on the yoga pro 2 is awful. I am not sure what Microsoft did to get precise control but it's the closest thing to mac track pad control I have found.