Switching to the new Macbook Pro

I am seriously considering switching out my 13" late 2008 (or 2009, cant remember) MBP for the new 15" Retina Macbook Pro. A little worried about a few things though. The first is the size difference. I am used to a 13" screen, so I am wondering if the 15" of screen will impede portability. How have you guys found it? Is it worth waiting till October to see if they release a 13" version?

Also, how have you who have recieved a new Macbook found it. Have you had any problems with it? How are the fans and heat? So many questions to ask!