What exactly are you looking for?
One is Windows, one is OS X - shouldn't this be obvious to you? No, this isn't an OS X is better dig, but I'm genuinely asking don't you know what you prefer?
They have obvious, apparent differences. What do you want out of a computer? Not enough information given.
Not greatly familiar with the latest renditions of Windows, and certainly not with version 10. Don't have good memories of previous Windows versions what with having to defrag all the time, use CCleaner, endure lengthy Windows updates, etc. If that still happens with Windows then I would not be thrilled. I may have already answered my own question, but I just want to make sure of all the details as I will be upgrading. I certainly like the versatility of the HP with the tablet, and touch screen features in addition to having a standard laptop. I have no wariness when it comes to the Mac OS, but I'm still wary of Windows. If there was a Mac hybrid, I wouldn't have any question or qualm.
Sounds like so prefer OS X and the decision is clear, so...? However, if you want raw opinions, then here is mine...
Windows is abysmal, and hopefully Windows 10 resurrects this. Windows XP and Windows 7 were good performance and interface wise, but its still Windows. The amount of updates is horrendous and its a huge buzzkill to see that forsaken icon reveal itself in the notification area. The maintenance is equally cringe worthy. Windows 8 makes me want to catch fire and have cinders embed themselves in my eye sockets before suffering a flame riddled death. It starts up pretty quickly, but I feel like I need medical attention when I go to use it. It makes me question my existence as a human being.
I would only ever go near Windows if it were required by software needs. FYI you can always put Windows on your Mac.
That is all.