i believe thta you misunderstood the issue with replication.

Fred Travis and Keith Wallace published their paper:
"Autonomic patterns during respiratory suspensions, Possible markers of Transcendental Consciousness"
http://moscow.sci-hub.bz/7e79cb20aa45e1cf35d4b37885e8d68f/10.1111%40j.1… (CAPTCHA input required for access)
in 1997.
Kesterson and Clinch published their paper,
"Metabolic rate, respiratory exchange ratio, and apneas during meditation"
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.971.6317&rep=r… (CAPTCHA required)
in 1989.

The replication issue refer to is that Fred Travis has asked researchers into other meditation traditions if they have ever seen this in other traditions, and the answer has always been "no." A couple of years ago, I ran across a single case study of a single ch'an adept who apparently was showing the same kind of respiratory suspension during meditation, but that's a single case study of a single person. Other than that, there has STILL been no replications of those findings in studies of *other* meditation practices.

.

And my point was that if you only have time to do a single practice (and many people find it hard to fit in 20 minutes x 2 on a daily basis), it would be good to understand what benefits are short-term and what benefits are long-term.

Since mindfulness and concentration practices are not "resting practices," one would expect that any benefits from rest found in beginning meditators would tend to fade as they became more adept at not-resting, and indeed, that is what the only long-term, longitudinal study on mindfulness shows. Other benefits persist, including some that are not found, as far as I know, from TM practice.