Power Wheels vs. Go Kart

We've been debating whether or not to get Conner a power wheels. Every time we go to Toys R Us, he insists that we stop at the massively large toys. They're not too bad in price... and the one we had picked out was big enough for Addy to sit beside Conner as he drove. But the problem with this toy is that it doesn't involve any exercise. Our next thought was to wait for a couple years, and then buy a go kart that we could all enjoy. We're just not sure what we want to do yet, but Conner sure does love those big cars with the stereos!