thats one hell of a guarantee.
90% of the people here recommend not using dreamweaver, you recommend it but you also are clearly rather cocky and make real out there assumptions so your recommendation doesn't really hold much weight.
only thing i can guess is that you are terrible at using programs like notepad so dreamweaver is twice as fast, but most other people can hack their way through "real" stylesheets easily.
a person working on a sites layout wouldn't need to open up the stylesheet as they are working on the sites layout. it's like saying dreamweaver isn't as good as you have to open the program which takes 3 seconds longer then something like notepad++ or jEdit

. As has been suggested programs like jEdit allow for many different tabs to be viewable in one window, so you can have the html/js/php/css all viewable on 1 screen, easily findable and easy to edit. i have 5 stylesheets for a personal site i made to learn php, each has around 1700 lines, and i can still tell you exactly where each element is getting it's style from roughly exactly where it is. and you can double my speed to make a site just because dreamweaver is that much quicker?