Well, based on your hostility to anyone who disagrees or questions you here, I'll bet you have zero interest in what I or anyone else who doesn't agree with your preconceived notions has to say either way, whether i waste an hour preparing a specially-written report for you or not. I stand only to lose only more patience and time repeating myself to gain nothing.
So, briefly, Yes. I have two offices of 24", 22", and 27" cintiq's for my designers, engineers, and architects, have run iPads since day 1 and have joined the staff in using and evaluating every illustration and design app in the App Store. One of our partners lent us an early Pro with a Pencil. They are two entirely different products with entirely different and the only overlap between them is the ability to sketch & paint on screen. If that's your only use for a wacom, then you might as well do it on an iPad Pro. It [will] work well enough for that. ...once the applications get up to speed. Right now it's a handful of raster apps with wildly varying performance. Vector applications for scalable, editable drawings are a ways out yet. On Screen CAD work isn't coming. Parametric 3d modeling isn't coming. etc etc etc. To do all the other things a professional designer does, and do them on an Apple computer, you need OS X and its ability to also run Windows. The downside of a cintiq, if you've never even seen one, is that they weigh a ton and are not meant to be mobile, or even really portable.
It doesn't take in-home brainwashing to realize why Solidworks wont run on an iPad, or why Dassault Systemes, Autodesk, Creo/PRO-E, CATIA aren't bringing their full featured professional design software to OS X or iOS. iOS devices are lightweight mobile devices for lightweight work. If you can't see the difference between the two, I'm not sure there's anything anyone can say to help you. Buy one of each and learn for yourself.