I'd love a Surface Pro 128gb, but the price is too steep for me to warrant. The laptop comparison is valid in a lot of areas, but I don't see it as a big negative that you can't sit with it on your lap, because I don't do that directly with laptops at the house either (always have a little tray under them).
Comparing the Surface with an Asus Vivo Tbalet smart or an Samsung 700 Smart or Lenovo, it's also better than them. OK, the price is the problem. Given the fact that an MacBook Air is just a China Production, as every other hardware product, the surface is produced by Samsung if I'm not wrong. That would also shows that the quality of the product is much better than that China stuff and also much more expensive in regard of manufacturing cost's. It should be a well known fact that the profit margin of Apple product's is terrible high, something which we couldn't say about Microsoft product's! I hardly believe that the Surface Pro will be "Flop"! OK, it will not get adopted as fast as an Apple iPad or an MacBook Air, but I think that the Surface will be well adopted by corporate users because it has the huge advantage to be able to run standard PC Applications, even some with no "Touch" features. For that the Surface get delivered with an special Stylus Pen already. Anyway let see the next 2-3 month!
I'll buy a real piece of hardware from an OEM, not no overpriced POS that gives you limited usable space (as vymrdal mentioned)
Before I would buy an Apple "Junk" I would even go with an MS "Junk" to know I get a bit more for my money and for sure, better quality. Till now the "OEM's" couldn't deliver the same Quality of what MS is delivering. Even the RT Version were much more bad than the Pro is, it were already better than the Apple "Junk" and others incl. Asus, and Lenovo. Only the Samsung were the nearly the same as the MS! Till now my Android Tablet wit IPS Screen is still doing what I need it for and as long as it did, I'll not change. If I change, for sure I'll go with the Pro if there isn't a better one in meantime. The weak point for me still is the Battery of the Pro. But that could also change in an short time. Let see!
I bought the large version. After deleting the 9GB recovery partition, which I don't need, I have 106GB of usable space. Given my experience with the programs I intend to install I will probably use about 33GB total leaving me 85GB for data. As far as I am concerned, for a "tablet" that's not too bad. Incidentally, the response on this little sucker is really snappy.