Haven't we put the "it's an accessory" bit to bed yet? It's awfully tired.
Also, the second someone needs to use that keyboard's bizarre-o trackpad to drive the software to write their term paper, you can bet the utility of having "traditional" apps on your tablet is going to be more carefully considered than simply assumed.
The argument against the surface remains that when you need a tablet, a 'full desktop OS' is not a feature you care about. And when you need a 'full desktop OS', the surface may not be a very good one.
So the comparison will, again (and as it almost always does) hinge on what people need or want these things for and how good each product is at performing those tasks in reality.
Also, pretending that all the iPad brings is ecosystem is just as silly as flatly stating the iPad as more elegant.