Since no one has mentioned it, I think, I'll add the Made in USA Kangaroo Caddy.
My wife and I have had four Clubrunners, two Powakaddys, one Robokaddy and two of the original Bag Boy Navigators. The last Navigator she bought for $100 at a thrift store.
The Bag Boys are still functioning fine but about a year and half ago we got tired of trying to wedge two bags and the two Navigators into our Acura wagon and bought a pair of Kangaroos directly from the company at the end of their "model year" on eBay.
Sadly I missed the $1100 floor models and ended up paying about $4,000 for the pair.
Their biggest advantage is that they come apart into three pieces, which makes it easier to get them into a vehicle. (The Bag Boys are huge, even folded up.)
They are the only remote cart I know of that has front-wheel steering instead of separate motors on the back wheels. They are built like a tank, and weigh like one too, as there appears to be no really light parts in them. The handle and front wheel "spines" are large-diameter stainless steel tubing.
They are, however, noisy in operation. And if you run them into a bush, they don't back up, so you have to go rescue them.