Nice thread, long time meditator with 6 years serious mostly daily mediation time including two 6 month sessions with several per day but what-ever, that is my ego talking.

Our meditation experience changes even as our diet/sleep/life changes, like our experiences with DMT.  We do progress and learn with practice.  The thing about true progression is how we carry ourselves and what we do in our lives.  For example 1 hour building a new neural pathway and 16 hours strengthening the OLD habitual ones and guess what happens? little change.  As others have mentioned it really takes exploiting that GAP and deepening the new pathways, disrupting the habitual.  This is the basis for Neuro-plasticity and it begins with identifying the gap, becoming the observer, recognizing transience, and building equanimity. 

a few months ago I was given a muse headband (monitors brainwaves during meditation) and although each day/moment is different, I did two experiments with DMT using it and posted them in the Meditation POLL thread.  I wasn't sure how to link it.