I like that the Surface 2 was interesting enough for you to review and you make some good points. For example it really is not the best for lap use especially if you are trying to use the touch cover. Using it on a bed or anything not solid is also awkward. It's possible, but not ideal. I also agree that the desktop is a clunky remnant that needs to go away if the Modern UI is to become more streamlined and easy to use.
However, you seem to gloss over a lot of the strengths of the Surface. You give the snapping of multiple apps a good view and do mention that is something it has over the iPad, but you seem to view the kickstand as more of a liability than a nice feature. Sure it doesn't work well in every case, but I'm glad it's there and it's unobtrusive. I'd rather have it than not and the iPad does not have it.
Dedicated USB port. Plug in a mouse, keyboard, printer or a lot of other USB devices and it will work. Flash drives work, game controllers work. It's a great feature that the iPad does not have, but you glossed over it and even attempted to view it as a downside since it limits how thin the device can be.
Micro SD expansion is huge if you want to add additional space to your device or want to transfer some files to and from the device. Like a USB flash drive it's something the Surface can do that that the iPad cannot do out of the box. Also USB drives and the SD card work more or less how you would expect them to work in Windows.
Built in micro HDMI. Good if you want to connect your device to a TV or monitor. Something you need to purchase a dongle for in order to do the same on the iPad.
Near the end you say, "But the iPad -- free of a keyboard, not reliant on USB accessories, and in a more handheld-friendly 4:3 screen ratio -- is not tethered to a desk. It's a dynamic device that can be used as a notebook if you really want it to be one. Or it can be something else."
You seem to have disregarded all the strengths of the Surface that you wrote earlier and turn them into strengths for the iPad. The Surface does not need a keyboard, but you can get a nice one and it's great for using "real" Office with. The Surface is anything but reliant on USB accessories. I'd argue the iPad is more reliant on dongles to add features the Surface already has built in. The Surface is not tethered to a desk. You can use it as a tablet, you can use it on a desk. The Surface in my opinion is the more dynamic device that can be used in more use cases.
A few days isn't enough to get a good feeling about a device you have never used. Other use cases of the Surface were not mentioned. For example using the micro HDMI you could connect your Suface to an external monitor. Add a bluetooth keyboard and mouse and you have a device that you could arguably use as your only device. Unplug the hdmi connector and you're good to go out with the exact same device you were just a second ago using as a desktop.
The Surface 2 also comes with 200GB of SkyDrive space for 2 years. For those who are okay with living in the cloud that's huge. It also has a year of international Skype, big if you call abroad. The front facing camera has been improved as well for better video chats.
I give you credit for trying it out and also for not using the app count argument as one against the Surface. In my opinion the apps are the weakest part of the Surface. It's something that might improve as time goes on but right now there are too few apps... especially games. You have some good points, but I think you have only scratched the surface of what the Surface 2 can do. A few days really is not enough time to try to compare it to a device that people have been using for years.