Re: Opinions and thoughts please...
At the recent seminar by Nevelius sensei and Ostoff sensei in Seattle, one of them (I'm sorry to have forgotten which, but it was a long weekend!) said that you should always fall from your best place. Either you are in a good, centered, stable position--and then it's reasonable to stay there--or you aren't, and should fall and get into a better one. But don't struggle along in a compromised position, tiring yourself out and making the ukemi harder.
Martha Levinson sensei, the seminar host, once told me that when you need to fall you should go down 100% so that you can immediately try to come up 100%. Fighting against the fall makes the recovery slower and more awkward, and you can get stuck. No good being off the floor, if you are in a position where you can't fight or protect yourself. She demonstrated with nikyo--if you go down immediately and sharply on the nikyo, sometimes you can bounce right up and reverse nage. If you force nage to grind you down slowly, there is no reversal.