[H] to wait or not to wait

[Winterlight]

I want to buy a new laptop, and I know which one = Spectre x360 
13-4005dx . But there is a problem. Windows 10 is supposedly coming 
out in late July. There are always upgrades on the horizon  but this 
should be a major change. That said the Spectre laptop just appeared 
in March and HP certainly didn't hold off bringing it to market.

 I haven't worked with the Win 10 preview, but I know it will be a 
free upgrade. My concern is will the hardware OS match be as good 
with Win 10 as 8.1.. or should I wait?.... or maybe it won't matter? 
I need the advise of the collective?

 Also has anybody heard about the Win 10upgrade matching the 
existing 8.1 version...i.e. if you have PRO do you upgrade to PRO.

 Thanks!