Love it how you downplay the MBA advantages whilst individually listing every sensor on the surface as a feature! Also pretty sure the MBA has a light sensor.
Now, what you didn't mention was performance and usability.
The MacBooks have the best touchpad of any laptop I've ever encountered and their keyboard experience will be much better than that of the surface.
The base MacBook Air will have a faster CPU and much faster storage as well as having 128gb vs 64gb.
Importantly, the surface, if used as a tablet has the downsides of an ultra book (increased weight vs ipad or android tabs, battery life of an ultra book) and when used as an ultra book has the downsides of a tablet (second rate keyboard and trackpad).
As a device, it's still a compromise - it's a decent tablet and a decent ultra book with some usability issues compared to buying both devices separately. Some people would prefer the best in class ultra book AND the best in class tablet, which be attained when these are purchased separately.
Lol you sure are all over this forum trying your best to scrutinize the SP3 with selective, biased, and uninformed information.
As I said in the beginning of my post I approached my comparison objectively and compared the specs and price as listed on each product's webpage. If I missed any specs, features, or advantages I'm willing to concede those mistakes such as the case with the ambient light sensor. However, I will state that mistake was due in part to the feature being listed under the keyboard section on the MBA product's spec page. That does bring up the question, is that sensor solely for the backlit keyboard or does it also function for automatic screen brightness adjustment? I would assume both, but not sure given it's placement in the specs page.
Regarding performance, if you are to compare two products on that specific category, its best to select two model with comparable CPUs. You selectively point out the SP3's base model and compare it with the base model for the MBA which starts off with a higher class CPU. That is why I selected the i5 SP3 model which also happens to have 128gb of storage making your point on performance and storage moot. On that note, I'll also bring up the fact that the SP3's i5 configuration offers a newer and higher clocked CPU than that of the 11in MBA.
As for usability, specifically on typing on ones lap, I did acknowledge the MBA's edge over the SP3, but if it comes down to superior typing experience alone there are hundred of dedicated keyboard(usb or Bluetooth) that are far superior to the one on the MacBook Air.
On the subject of compromises, I would argue again that it comes down to personal preferences. Another way to look at it is, as a tablet the SP3 is far superior to the iPad in terms of power and productivity, also pointing out that the excellent battery life and light weight even if heavier than the super light iPad air. The fact the iPad air get slightly better battery life and is lighter doesn't take anything away from the SP3. When an iPad air 2 is released and it's half the weight of the original air it won't make the iPad air a bad tablet. In terms of it as an ultrabook, it has the added benefit of being extremely portable, allowing you to use it in situations where even a super light ultrabook would be awkward to use and the power is on par with and in some cases superior to even the most popular ultrabook(MBA 11 cough).
Your problem is that you insist on looking at the SP3 as being a glass half empty while it might not suit your needs it does for others. It comes down to getting what works best for you. In my case, I'm willing to give it a try and trade in two products for one. If my hunch is right I will be a very happy customer. while others deal with their "best in class" products and all the hassle that comes with carrying two products and chargers.
