It's telling that those jira tickets are both in the top five most voted on open server tickets and are from 2010 and before. (I know you know this roger, but) TokuMX completely resolves both of them.
But does TokuMX solve all the other issues like write concurrency, eye wateringly slow (and single threaded) index building, or there being no way to practically reduce the file sizes. (repairDB takes forever and requires the same amount of free space as already used, and compact also needs free space and doesn't remove any files).
Write concurrecy: yes, TokuMX does not have a database level reader/writer lock.
Index Building: yes, fractal trees can write data much more efficiently, so if index building is a problem, I bet TokuMX solves it.
Practically reducing file size: to be honest, I am not sure because due to our great compression, this has not been a general issue for our users. Our reindex command could reduce file size, but I cannot point to examples.
One of our big goals is to address storage issues MongoDB has.