I use vbdrupal at
http://www.alleria.com
I spent a lot of time playing with standalone drupal, but when vbdrupal version of drupal 4.6 went stable, I jumped at the chance.
We use a lot of standard drupal modules, integrates beautifully. I think vbdrupal is truly the power admins CMS. If you get used to templating and skinning systems easily, its a breeze, and the level of control is awesome.