The Wand+, which comes in black or white, doesn't seem heavier in any way, considering it technically has more hardware packed inside. In terms of battery life, we also didn't notice any discernable difference in drainage times. This makes sense, as we never experienced increased battery drain when using the Wii MotionPlus plus attachment with standard Wii remotes.
In our testing, we found that the Wand+ worked just as well as MotionPlus. Wii Sports Resort noticed MotionPlus right away as we tried out ping-pong and Frisbee toss. There haven't been too many MotionPlus-compatible options in the Wii library, but support for the technology seems to be growing as of late. For example, NHL 2K11 fully supports MotionPlus, and we absolutely preferred playing the game with the Wand+ over a Wii remote and MotionPlus combination.