Dom Cardine's last will and testament (a PDF file) introduces some rather hard-to-follow complications on the road to semiological perfection in understanding chant rhythm. I would except it but I'm not even sure what passages to quote. I do notice that he expresses profound respect for the work of Dom Mocquereau. Those who are interested in the chant-rhythm controversy will find it enlightening. Those are are not interested will find confirmation that they aren't missing anything.
(Coda: Here is a quick cut and paste)