Just updated BobbyMods to 6.11, and for the sites that I set up and manage it was an uneventful affair.
I also updated a couple of multi-site installations, and if you didn't hack core and put the themes and modules where they should go (as opposed to where-ever it works) it should be fairly easy.
In 2004 I developed an affiliate web site in dreamweaver and I have done some minor maintenance on it since then.
Now the owner wants to be able to edit everything from his favorite coffeshop.
Anyway this is a great candidate for a straight migration from html to drupal.
He doesn't want to change the design of the website, actually a change is ok "as long as it is a bonus" but he really needs the ability to edit and configure, so this should be fun.
Main points are;
Ok, I had my web development site running on an older version of drupal with a nice collection of modules.
Well, the newer core versions came and the non-core module updates didn't! (not in time for me anyway)
No Problem, except for two things;
A new start can be a good thing and is in line with the drupal "no backwards code compatibility" guideline.