Rob,
I'm a fan of coordinated dual CSI and Project folder structures, myself. I like to keep standard details linked to CSI folders always so that any changes to standard details ripple into past projects that reference them. This is the big controversial decision - a lot of offices don't want past projects to be auto-updated.
I personally felt the pros vastly outweighed the cons. I didn't see fixing glaring errors in a past-project's detail that was already approved to be an issue. For instance, there was once a gate detail that, as drawn, was not physically possible to open the gate.
Fixing it across the board instantly was therefore a great benefit, and I decided that if anybody complained that the detail changed, I'd deal with it on a case-by-case basis. No cases where somebody (contractor or otherwise) complained about it ever came up.
Now, I'm one of the biggest CSI cheerleaders, but there's definitely a time and place for a project-specific detail. I like to limit that to only details that couldn't possibly EVER be used in another project, such as a entry feature with the name of the subdivision on it, or a custom sculpture. Now they may be based on a standard detail, like a standard pillar detail that you customized to add the initials of your client in a cast plaque. I just like to keep one-time use details out of the CSI folder so they don't accidentally get used again. It also keeps the clutter to a minimum.
A lot of users elect to make copies of everything, though, like you're contenplating. They maintain a single standard detail that gets updated with any fixes to problems with it, but make a copy each time its used in the project folder to make sure any future changes don't affect past projects. It ends up working very well, too, and has the benefit of constantly making copies of old versions to go back to if an improper edit is discovered.
Having maintained an office detail structure while being a project manager, I needed to make it a habit on myself to always double check the details that are placed on the final plan to go out to make sure firstly that the correct detail I wanted used was actually used, and that there are no errors I can see on the detail being used. That check helped me constantly re-evaluate our standard details on a project-by-project basis, helping them evolve with evolving field experience. Edits were always done on the original standard detail. With copies, you'd need to then apply those changes to other projects as needed as well. It could be a lot of editing.
As for the new updated CSI structure - thanks for the prodding, Seaweed. It gave me some ideas on how to roll out the CSI folder structure updates in a way that works with the existing CSI libraries out there.That's mostly what I've got left to work out before releasing it.
-Amanda