[Russ]

You're not missing much as a PC user - I too was hoping for a more traditionally functionable start button. Other than any 'under the hood' changes all I've noticed is the Store button on the taskbar (useless as I rarely if ever use the Store). Also clicking on the start button and going past the 'Metro' screen allows you to sort the apps in to most used, name, date installed etc which I guess is a bit more useful. Not sure if you were able to do this before but you can also shrink the taskbar to about half the width which will help if you have a small screen.

There may be other cosmetic changes but for how I use my computer that's about it.