I finally got the Milwaukee wrenches in today, so bear in mind this is only first impressions. The 5-6 points of contact between the wheel and jaw definitely help over typical 4-slot wrenches, and the machining seems to be to much closer tolerances on this one too compared to typical cheap wrenches with wide channels that barely engage smoothly. The slop in the 10" looks to be about half a mm marking, so around 1/64 of an inch, maybe a touch less. The small 6" one is even better, barely the width of one of the line markings on it if I’m really trying, and bordering closer to almost none. I think the slop on it comes more from the entire jaw’s bar slop in the guide holes than slop in the hand wheel moving back and forth.
Compared to a general wrench like Husky or Kobalt, these are definitely a big step up. Compared to the other adjustable wrenches I own, very old Crescents and more recent blue-overmold handle Irwins, these have less slop and hold better. I don’t have any “high quality” wrenches like Bahco or similar to compare, nor do I have channellock or Irega wrenches, so I know it doesn’t help your question a ton. We’ll see how they hold up through some use, if they loosen up any from new out of the packaging. I will say they feel pretty solid, have a good weight to them, definitely better than any other HD or Lowes stocked wrench I’ve ever handled. The adjustment wheel is easy to roll with one finger, there’s no sticking or jamming or that occasional annoying catching when a new tooth tries to engage like cheap wrenches have. For the price ($25 for the pair from Acme, less if you use a coupon), I think these are going to be the ones to beat.