Returned my SP3 today. Although it is a nice unit I can honestly say I am happier with my SP2. I find movies to be clearer and the smaller form factor easier to travel with and use on the road.
I find the Pro 3 to be as easy, or easier to travel with than the Pro 2. With the Pro 3 being thinner and lighter, but still only an inch wider, it's almost perfect. After owning an RT, Pro, Pro 2, and now Pro 3, I can state that for me the Pro 3 is by far the best.