W7 is Vista underneath except that MS spent much effort and money making it work. I would go so far as to suggest it really is the best OS MS have ever produced. It is quick, doesn't crash or hang and is much, much better in its layout and functionality.
I have had but one issue with it where a window pops up and says Internet Explorer has stopped working and needs to close. I find if I click the red x in the top right hand corner the warning window closes and everything carries on as normal! I can live with that.
I understand people's reluctance to change when I look back on the amount of crap that has emanated from MS with each new release of Windows but they do seem to have got it about right with W7.