I’m in the same position, none of the solutions suggested so far has worked for intellisense (the build times fix did work awesomely though).
I’m running an i5-3570K, 16GB of RAM and an SSD, so I’m pretty sure it’s not a hardware problem.
Also, sometimes it seems the whole setup gets confused, i.e. strange compile errors, and a simple restart of Visual Studio (without changing any code) fixes it.
I must say this is making it quite hard, especially being new to C++. In addition to considering my own questionable C++ skills, I must take Visual Studio’s feedback with a pinch of salt.
Intellisense usually kicks in after I’ve finished typing all the code that I want before compiling, and then squiggles start showing me errors which go away when compiling.