Apparently you have the money to dish out on the Surface Pro...I wish I did.
A comparison between those two is kind of unfair...mostly to the iPad. The Surface Pro is essentially a laptop and shouldn't be compared to the iPad as the iPad is still running on a mobile processor.
As for the Pro having significantly less than advertised space...my Windows 8 install takes up a little more than 10 gigs so that would be a sizable chunk but with cloud storage being as prevalent as it is, it probably isn't that big of a deal. The Surface also includes a full size USB port so using an external hard drive is entirely possible making the limited storage even less of an issue.
All in all, this shouldn't even be a comparison. If you have the money for the Surface Pro...go for it.
Now if you were comparing the Surface RT to the iPad that might be a little more fair.
The Nexus tablets are excellent tablets as well.
I do remember you saying you need powerpoint from your last thread...I should have asked there if you could use Google Apps for that. Google Apps can be utilized on essentially any device with an internet connection.