I have seen a number of posts on how good the regeneration is or isn't on our Leafs, and how it compares to Teslas. My impression is that there isn't enough "hard data" to do much more than speculate.
For our family's "use case", the relatively small 24 kw/hr battery on our 2015 "S" Leaf seems satisfactory. Rather than clamor for more, my inclination is to be ok that I'm not dragging around hundreds of extra pounds of battery for the very few times we drive more than 70 miles in a day.
It may be "confirmation bias" on my part, but I'm underwhelmed by the much larger Bolt and Tesla batteries allowing 200+ miles of range. IIRC, the batteries on the Tesla P65, P80, and P100 weigh from 1000 to 1200+ pounds, compared to the approximately 500 pounds of my 24 kwh Leaf.
But .... it does seem like if an EV has good to very good regeneration, that would significantly compensate for dragging all those extra pounds around.
Regarding range, weight doesn't hurt all that much once you get up to speed, but rather starting and accelerating. But if regeneration is efficient, then the extra weight might not be all that much of a liability.
I've been pondering if a reasonable estimate of regeneration efficiency could be calculated from comparing a hilly route to a flat route. I've read posts about that issue, but they seemed to mostly be guesstimates.
An acquaintance who owns a Tesla claims it has better regeneration compared to the Leaf, perhaps because it has two motors and perhaps less likely to be "maxxed out" when going downhill and/or braking.