Took a while to catch up in this thread in order to post my 2 cents worth.....
I am the type of player and especially the type of GM that detests nonsensical outcomes. I have played with players that think you can convince a random noble to sell his family into slavery, hand over their entire fortune to you and run naked thru the streets if you can roll 3 nat 20's persuasion checks in a row.
That is why I am liking where this system is going. Don't get me wrong, it is going to be a hell of a lot of work for the GM in large combat, probably requiring software tools to do effectively. But for players, same number of rolls with more dice, and the tiniest bit of arithmetic is not a lot to ask. Everything else is them being too afraid of what they will loose.
The example mentioned earlier about the initiative cost of having to move and heal (2 dice) being unlikely to save a party member from being merely stabbed by a stationary enemy (1 die.... hehe) is clearly one of those cases. To think there is any chance that a player can "walk 5 feet, climb a 5 foot wall, leap over a table, use my action to dash 30 feet, then cast a spell using metamagic as a reaction" before the enemy can "poke them with my dagger again" is, in any reasonable analysis, preposterous.
I agree that it does put a focus on more tactical type combat, and having a diagram or physical representation of the battle will probably help speed up decision making a lot. One example of a way this will go down well that I like would be as follows: I chose to stay right here and guard this spot. My enemy closes and attacks me. If the enemy does manage to win initiative (with a bit of luck on the multiple rolls) then they successfully hit me first. If, given that I have done nothing this round except prepare for the attack and have had plenty of time to have my weapon and armour in the optimum position (thus giving me the advantage of only rolling 1 die) I do win initiative, then I hold my action until the enemy closes, but then strike first because I am set and ready for the attack. The third possibility is that the enemy chooses not to attack me. Then of course if there is nobody near me to strike the attack is wasted, but that is the sacrifice you make for the initiative advantage.
One new idea that just popped into my head as I write this excessively long post (sorry........) simplifies it a lot: If you want an unrestricted turn where you can do whatever you want when your turn comes around, roll d20. If you forgo movement, as in you resolve to stay put and defend that spot, you roll a d12. If your only objective is to get the hell out of there, you may roll a d8 and your only options in the round are dodge <EDIT: meant Disengage> or dash--and offensive bonus actions/reactions are no longer an option in that round.