Many times over the years I have done what I call "Feldenkrais Deep Dives" where I work intensively with the Alexander Yanai sessions and others such as the Esalen workshop and do 2-3 sessions per day, every day, for as long as I can handle it.
The changes that I have created for myself by doing so have been tremendous. Doing 3 sessions a day for about 28 days is what finally got me to leave the U.S. in 2010 and move to Mexico. Several years earlier, in about 2006, I recorded and did the first 25 of the AY sessions and it gave me the huge revelation that my experiences in Feldenkrais trainings and workshops were useful - but not as deeply transformational as going into Moshe's core teaching.
Keeping off drugs, going to grad school (and quitting grad school), expanding my business, and moving to Mexico are all changes in my life that I attribute to my intensive of Feldenkrais sessions.
Update: I added an Alexander Yanai section to my growing Feldenkrais History page.