JCR experiences

Boris Kraft said in the thread "CMS Migration"
> With all these interesting things being said, maybe next time look  
> for a JSR-170 compliant CMS - it will not resolve all issues but at  
> least it is straightforward to reuse the old content with a new  
> system, and/or change gradually

At first when I read this I started to write a rabid denunciation of it
because from reading the JSR-170 spec itself and the press on it in the last
several years I haven't seen much real benefit to it outside of getting a
lot of direct and indirect press for Day.  And perhaps also because I'm from
"outside of the Java world" (meaning .NET, of course... aughh, I've been
stabbed by a PHP developer!) and haven't been caught up in the dream of a
JSR-170-filled future.  But the existence of CM technology standards is
certainly a good thing in general, and such vitriol is a waste of a good
list, so let me pose some more productive questions to the list at large:

Are there any client apps out there that work with CMS systems from
different vendors through the JCR APIs?

Does anyone have a good anecdote or two about doing some custom integration
between two different systems using JCR APIs?

Any anecdotes on porting from one JSR-170 compliant system to another?  Did
you choose to automate part of the process through the API?  If so, how much
time do you think it saved (compared to other ways of automating)?

Of the compliant products that you're familiar with, how many implement
Level 1 compliance, how many implement Level 2, and what compliant
implementations of the optional features do they do?