Personally I think the product is incredible in many ways, and overall very overwhelming/impressive relative to my expectations, however to me it has two very core faults:
1. Performance. Many actions are perfectly fine, however v things like videos can be choppy, and even reading a Kindle book is choppy.
2. DPI of the screen. It's a nice screen, and the responsiveness even beats the iPad (incredibly), though after using new high-res displays, the Surface screen looks pixelated (primarily when rendering text).