Although I do love using my Windows Surface Pro 3 I do find the flexible position stand uncomfortable to use on my knee. The Surface Book is more of a convertible laptop being able to be used as a Surface and a traditional laptop. The drawback? The price! Predictably at £1,499 rising to over £2,499 at the top of the range. So it looks as if my knee will continue to suffer! Not sure that with a small SSD as well( although with my Surface approach 3 I have never find this to be a problem!) I would be able to make this my laptop to store all my specialist software on as well . But it looks a good machine and wait to see how users respond. I think that that price in comparison to say – an acer or HP – will not make it a popular choice!