oh, i agree with you on using the iPad in professional ways, i've done it myself. but did you use the surface 3 or the 2? i've heard the 3 was a big step forward, and it's the only one i've played with, but only for about an hour. photoshop seemed outstanding when i tested it. it's i'm sure a lot to do with personal preference tho.
The surfaces are about to turn the corner and take over... the Surface had one crippling issue.... Windows 8.1 was trash... with Windows 10 coming shortly and the next version of hardware the Surface is going to be a legit #1 contender in the PRO space. I wouldn't be surprised to see by October a launch of the new Surface in 3 sizes, all a fraction over each of the three ipad sizes and with the same or slightly better pixel density.
ipad - surface
7.9 - 8.1
9.7 - 10.0
12.2 - 12.9
I would easily switch from my current thought of going iPad PRO right to the Surface.... Apple has to consider that a false move with the PRO looses a large wave of customers for 3-4 years, and hurts their chance for a repurchase from those consumers in 2020.