It's all a moot point anyways, since like every other laptop I've checked on their site, this is out of stock. Not sure how HP expects to sell any products when it seems none of them are ever available for sale.
I mainly like the idea of a ProBook because it's one of very few opportunities to get a laptop without having to pay for Windows, which is ridiculous. And HP (as well as probably others) like to claim that they buy the licenses in bulk and so they're cheaper and can't be broken out from the cost of the computers, yet here they are, offering one without it (so why can't they do that for all of them) and the cost to add a license is comparable to retail cost (which is both stupid since you're paying retail for an OEM license and proves the point they're charging a lot more for the licenses on their other computers than they want you to believe).
As for Surface being representative of a "flagship premium" device, I have to disagree. I have a Surface, and I can't wait to get rid of it. The thing has so many problems and is the biggest POS I've ever seen. It's more like an example of how to take what could have been a great computer and completely ruin it by making it complete junk. Never again.
And more important than the power button, IMO, is volume buttons. It amazes me that NONE of the convertibles I've seen except the Surface (which I don't consider a convertible; it's a tablet with an attachable keyboard and is extremely poor at being a "laptop") bother to put volume buttons on the side. They all love to advertise all the different "modes" of use, i.e. tent, stand, etc, yet they don't bother to add such a basic feature that's very important for actually using the computer in those ways.