It's always a conundrum - one longs for cordless appliances! I have both - outlets where they already were (remodel, not new-build) and I think they are best. I used a white honed marble backsplash and was able to find some matte finish white porcelain switch plates. In another place, a wall outlet was not possible due to other "stuff" being there, so I used a plug mold strip behind the under cabinet lighting. It's great except that virtually all appliance cords in a kitchen are BLACK - if only white were an option. No, I don't care enough to unplug my toaster oven after each use - it's my kitchen, not my LR.

If money had been no objections, I might have considered using one of the pop-up power outlets, but I'm not sure how they work with drawers below plus they cost in excess of $500 just for the device.

I really think if one can find switch plates that work, low wall outlets right behind appliances are the best solution.

We put them in behind our lights up high. We do not keep many appliances plugged in so that's not an issue. I like how there us a recepticle every 4" and hidden. Our electrician was not a fan of installing it but I like the outcome.

Remember you'll want several circuits.

I used white subway tile for my backsplash and the white switch plates set horizontally blend right in. Doesn’t bother me at all. Cords trailing up to my cabinet bottoms would drive me insane

The outlets on my work wall will be low for the frequently used small appliances. The coffee station outlet will also be low, since we don't unplug the unit often. I'm probably putting plugmold (which is what you're asking about) on the cleanup wall. It'll be convenient when needed but tucked out of sight since it won't be an appliance heavy area. I honestly don't know when it'll be used but outlets are required.

For our area, outlets can't be located higher than 20" above the counter. This works fine with plugmold since uppers usually start at 18" above the counter.

Determine your local code first. And around here, I took the minimum needed distance between outlets (by code) to be a guideline... and had them put in more. At any rate, lower is better so cords don't dangle, assuming your code allows. I don't have a ruler to hand, but i am guessing the centerpoint of my outlet plates is 4 inches or possibly less above the countertop here.

I think the answer depends greatly on design and your use patterns.

We have a large toaster over that we have planned its location. We know where we are going to do the plug-in-only-when-actively-using items. So vary it up. Code requires certain plugs that many people will not use. Use plugmold there. Try not to be confusing of course but keep it to a sensible plan.