First of all I think it is important for me to state how I personally measure what I think makes a rule or a system good or not. Well, to be honest I just go with gut feeling and experience, but if I am going to be writing about this, I should try to come up with some explanation of what is important to me.
The Three "F"s : Fun, Fair and Fantastic
Dungeons & Dragons is fun. If we didn't think this we wouldn't be here. But that does not mean that everything about it is fun. Something can be fun overall, but have aspects that are painful and awkward. When I am looking at a particular aspect of D&D, I am trying to judge for myself whether it adds to, or diminishes, the fun.
Fairness has never been something D&D has worried about, even when it really should have. The attitude for most of it's history has been that you do not need to be fair because it is a cooperative game. I couldn't disagree more. Everyone at the table should be able to contribute to the story, and not feel like they are the assistants to someone else.
Fantastic, as in "being a thing of fantasy". Realism is all well and good, but D&D is not a realistic game. Rarely has it claimed to be realistic, but often it has attempted to be realistic. People use different terms without, in my opinion, really considering what they are trying to say.
I will go into more detail about this.
Realistic: This is trying to make something as accurate as possible to how things work in the real world. D&D isn't this sort of game.
Believable: This is trying to make something feel like it makes sense within the defined setting. It is the word bandied around by a lot of people who know that D&D isn't realistic, but they want to keep it as close as possible. This is a fine attitude to have, but too often it will come at the expense of either the Fun or the Fair.
This is why I went for "Fantastic", if I was to be honest to myself the word I should be aiming to use is verisimilitude, but it's a pain to say and it confuses people. So I decided to settle for Fantastic.
When a Wizard uses his magic to drag the hippogryph out of the sky, that isn't realistic, it's Fantasy. When a Fighter jumps onto the dragon's neck in order to bury his axe into it's skull, that isn't believable, it's Fantasy. I want to feel like the actions taken by the characters and creatures in my D&D game to feel like they are part of a fantasy world not just with their special powers, but in the way they act, the way they think, and the way they talk. To them, it is realistic, because that is the world they live in, and that world is Fantastic.
You want there to be some form of internal consistency to the story, especially if you want it to be Fun and Fair. Just because something doesn't make sense from a realistic point of view doesn't mean that it isn't the right thing to bring the Fantasy, but you don't want to take it too far. Verisimilitude is what we are aiming for, but Fantastic works if you think about it from the perspective of adding to the Fantasy.
I expect this is the concept I will have to spend the longest explaining when I use it, but I hope people understand what I am trying to say.
So this is my starting point for looking at the aspects of different versions of D&D and other RPGs, including D&D Next. Fun, Fair and Fantastic. If something contributes to those, then it is probably something I will be supportive of. If something works to the detriment of those, then it will have a much harder time justifying itself.
So when someone, including myself, tries to claim something is better or worse, they better be prepared to explain their thoughts from these perspectives. How does it add to the Fun? How is it Fair? How does it contribute to the Fantasy?
If you don't want D&D to be Fun, Fair or Fantastic, I am not sure why you are playing, or why others would want to play with you.