Began researching them myself over the winter. I would definitely purchase one if it weren't for the fact that part of the value of my course membership is that I don't pay for carts. So, if I don't use a cart, I feel like I'll be getting less of a deal. However, IMO, walking is far better for your overall play from a focus and concentration perspective. So, I'm torn. When I walk and carry (usually nine practice holes late in the day) I feel so much more in-tune with my game.
I have been really interested in the Stewart X9 (@$2500) and the MotoCaddy M7 (approx $1700). They are both in my "strong considerations" list for when the time comes that my membership is over about 2 years from now. I'm of the age where a retirement in the south somewhere may be in order soon. I'd then be all over an electric walking cart. I'll have to keep as much of that Social Security check as possible in my pocket. 😆