They do take some getting used to. I bought a pair of the Lone Peak 3.5 at REI's anniversary sale, and have been walking 5-8 miles a day about 5 days a week, and I still feel a slight tightness in my calves toward the end of my walk. I haven't experienced any pain or anything, just a different feel.

These have a fairly thick, somewhat soft insole that feels nice and cushy, but I got some of the flat green Spenco insoles which are thinner and firmer, and I like them better (had to get extra-large ones so I could cut them to fit the wide toebox.)

I've ranted fairly often about such things in the past. To recap:

Zero drop is good...pretty obviously the way nature intended.

Arch support is unnecessary unless there's a condition that requires it. Years ago I used the Superfeet green insoles, and found that my feet would ache if I walked five or six miles without them, in sandals for instance. Once I stopped using them, that changed. I suspect having constant support weakened my feet. I think some support may be desirable when carrying a heavy pack, especially over a distance longer than you're used to.

Everybody's feet are different and others will naturally have different opinions. I think it's important to remember that shoe (and insole) manufacturers are interested more in selling shoes than promoting foot health, and don't necessarily have that much knowledge about the subject anyway. We're kind of on our own.