I use a Sony VAIO duo 11 tablet with an 11 inch screen. Has windows 8PRO and 8 Gb of RAM. I carry the tablet from room to room. Tablet works very well, because the screen size is good. AC works well on this tablet and I think it would also on the surface PRO. Please note when AC runs on Windows 8 you do not have the ability to "pinch zoom in or out" so it will be difficult to show a parent a growth chart. That is one of my problems with AC's growth chart. Have you tried bringing a part of the growth chart in the enlarged display window? using the horizontal and vertical tabs to bring a particular chart into view is VERY slow.
The tablet is on the network through wifi and speed is acceptable.

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Raj
From (mostly) sunny Port St Lucie, florida