I basically only use mine in desktop mode. Problem with desktop mode is the onscreen keyboard does not adjust the screen so its an overlay. Also annoying is that it won't pop out without specifically clicking the keyboard icon. However, onscreen keyboard works well and is actually large enough for me to type like a on a regular, you'd just have to find some way to place it to do so.
Metro is where it makes more sense to use it in tablet mode, but I mostly only use mine like that with one note. Also mine seems to have a bug where 5ghz WiFi doesn't work in metro, but I can't seem to find anyone else having that problem.
It probably would have made more sense for me to have gotten an ultra book, but I do quite enjoy the surface lineup. However, don't get the i7, it gets too hot so performance takes a hit as does battery life which can be very inconsistent.
Also if you don't need one for awhile may want to consider waiting a bit and seeing if Microsoft unveils sp4, which should have a broadwell chip and be cooler.
Only thing I don't like on the sp3 is the pen, I feel its a huge downgrade from 2 and I have trouble making it work reliably.