I started out with Pagelines a year ago and it completely changed the way I worked. Sites that would take me a day to create a working template were being finished in a couple of hours!
It's extremely flexible, The Professional and Developer editions have loads more features than the Lite edition, put that together with a little bit of Css and you're creating sites on the same caliber as some of the other 'premium template' themes out there, but to a layout and spec that you want. With the option to create your own child themes, add hooks and third party plugins, the possibilities become endless.
The more you learn and put into it, the more it gives back.