I have the surface pro 4! I didn't buy the surface book cause it was a bit too expensive and not much portable compared to the pro 4, and 3 hour battery on the table mode (without the keyboard) means you cant really use it as an ebook, pdf reader, etc for too long in my opinion. However the book is great for advanced stuff like gaming, AutoCAD (and similar software), VMs, photoshop, etc cause of the dGPU. Since I wont be needing those stuff, I got the 4gb ram surface pro 4 model and been loving it!
For the rest of the people (especially students), the pro 4 will be great! My 4gb ram is more than enough to browse the internet while also reading through textbooks and making notes through OneNote. The pen and OneNote combined is great for note taking, as it feels just like note taking on paper. With the preinstalled app, Drawboard PDF, you can easily annotate, highlight and do much more stuff with pdfs (especially those electronic textbooks). You can easily do these without the typecover, and then switch back to the keyboard when you need to do some serious typing in word or something.
As for gaming (if anyone's interested), I only tested out League of legends and minecraft, where league gets about 120 fps on normal setting and runs flawlessly. However the scaling is pretty bad, due to the aspect ratio and resolution (you can fix some issues, like the cursor size by switching to colour blind mode). On minecraft however, the fps was around 50, and this had to do with the game itself, cause some of my other friends also get low fps in their gaming laptop. The fans does turn on when you play games, even like minecaft, and also some heavy browsing (watching tons of youtube videos at the same time) and it is a bit loud, which might be disturbing. The battery life is average, and although I don't really know how much hours I get per day, its pretty okay as far as I'm concerned.
Regarding about the issues that everyone's talking about, the only one I had is that the surface would kinda overheat and fans starts to kick in when it's sleeping. Other than that, I absolutely have no issues with this. The reason why people think it has a lot of issues is that only the people with these issues speak out in forums, youtube vids, etc to get solutions. while the people without any issues remains silent. Sorry if I wrote too much lol, but I highly recommend the surface pro 4 (except when you are doing advanced stuff in which you can get the surface book).