Tesla's Autopilot has dominated the conversation about semi-autonomous vehicles and advanced driver assistance systems, but competition is mounting. Volvo has its nifty Pilot Assist rig, while Cadillac is working to take the driver's hands off the wheel entirely with Super Cruise in the latest CT6.

Great cruise stories:

It's difficult to overstate the impact that Super Cruise has on the driving experience. The CT6, as we found out during a week of testing, is already a relaxing car. But stick it on the highway and hand the reins to the computers and it becomes a remarkably easy car to cover long distances.

But Super Cruise does have its shortcomings, as does the broader CT6. It's saddled with a tiny cargo hold for a big sedan, at just 15.3 cubic feet, and to make matters worse, the powered rear seats don't fold flat. There's also a mismatch of materials in its otherwise well-constructed cabin. And the price for our range-topping CT6 Platinum is far from cheap, edging up towards $90,000.

But it comes remarkably well equipped for that sum. Aside from the well-executed powertrain – a 3.0-liter, twin-turbocharged V6 pumps out 404 horsepower and 400 pound-feet of torque, all while working alongside a calm, smart eight-speed automatic – there's a 34-speaker audio system. That's at least 14 more speakers than any normal person needs. A 20-way driver's seat is a fine place to while away long hours as Super Cruise steers you to your final destination, helped along by GM's excellent MagneRide magnetic dampers, which can smother potholes and imperfections without complaint.

To find out more about what makes the 2018 Cadillac CT6 tick, check out our latest episode of Why Buy.