Dad’s short answer: Mostly a good thing — they make a heavy machine feel effortless. But check that the drive fully disengages when you let go. I've tested one that kept creeping and drove itself away unsupervised, even after a firmware update.

Why power assist exists

A full floor washer with water in both tanks is heavy, and pushing one across a big kitchen gets old. Power-assist wheels sense your hand pressure and drive the machine forward, so you're steering rather than shoving. On the machines that do it well it's genuinely one of the best features in the category, and it's most of why a heavier flagship doesn't feel heavy.

One distinction worth knowing when you read a spec sheet: some machines list power-assist wheels when what they actually have is a spinning roller that pulls the unit along a bit. That's roller glide, not powered drive wheels. I only mark true drive wheels as power assist on my own spec sheets.

The failure I actually hit

On one unit I tested, the drive wheels would not fully disengage. Let go of the handle and it kept creeping. It drove itself away while I wasn't holding it, and a firmware update didn't fix it. That's a safety issue in a house with a toddler or a staircase, and it weighed heavily on that machine's score.

What to check on any unit with power assist: stand it upright, let go, and see whether it stays put. Then do the same with the handle at mopping angle. It should stop the instant you stop applying pressure. If it creeps, that's not a quirk you get used to — that's a machine I'd return.

Dad’s Take: Power assist is a great feature right up until the machine won't stop. Let go of the handle in the store aisle and watch what it does.