In my opinion CR is a quite good tool, and having a central service to handle all the content in the way that CR does is just good, as Talli stated, the only missing thing is the docs, which is not so bad at all, but if you want exploit all what CR gives you, you'll need to investigate (which BTW is what you usually do in a fast improvement project like oacs). Actually, just seeing how other packages interacts with CR, is in the most cases is enough to build your application, and won't take you a lot of time to understand if you are used to work with oacs. About portability, anyone can create its own schema for it or try to apply *some* standard, so your work can be used by others ...
About scalability, if you can do some scalability tests before you use it on production will be good. Keith, are you using PG or oracle? (I guess oracle)
Anyway, why you don't create some simple scripts to populate the DB (one photo album instance), won't be so hard and will give you a good look about performance in extreme conditions.
check this:
http://xarg.net/writing/tuning/forums-scale
or
http://viaro.net/tips.htm#scalability
