The DnD Next blog this week talked about some of the things that worked and didn't work in Next. The designers of Next really like Advantage as a mechanical replacement for the bazillion and one different +1s that older editions relied on. I agree, and have done the same thing in Heroes By Trade. Nobody really liked the system of
"I hit AC 21."
"Wait, I am flanking. AC 23."
"I have Cat's Grace up, AC 24!"
"Is that Prayer spell still going? Make that AC 25!"
"... fine you hit"
and replacing that and the terrible iterative attack system with a single unchanging bonus to hit and advantage / disadvantage is fantastic. Players should not spend half of their combat time and most of their thinking on locating all those pesky bonuses that have been misplaced somewhere.
The thing that makes no sense to me is that they still don't grasp the fundamental flaw with their skill system. I have said it before and I will say it again until they publish or listen - when being the strongest person in the world gives you a +5 bonus over a regular schlub you should not be rolling 1d20. The idea that an Olympic weightlifter is only a little bit better at lifting a portcullis than I am is ridiculous and makes the whole skill system absurd. If the strongest person in the world gets a +5 on me then we should be rolling 1d4 so that no matter what happens I am just worse. They tried and failed to implement an auto success system and their failure can be squarely blamed on this one critical flaw.
One thing I am not sure they notice is how much this impacts the martial vs. caster balance. If martials could rack up really big skill bonuses and actually do cool things like leap over buildings or smash brick walls then the endgame wouldn't feel quite so much like Gandalf adventuring with Pippin. Unfortunately with the enormous die and the small bonuses nobody can do anything really cool - unless of course they can cast spells. If you want to see a game where high level fighters can actually do something other than "Swing sword very good" then all that is required is a few mechanics to give martial classes large skill bonuses and reduce the die rolled on skill checks to 1d6. When something is hard for a normal person to accomplish at Difficulty 6 then the rogue with a Balance check of +15 can probably walk on raindrops.
This is actually making me reconsider my current HBT design. In the game characters can hit check bonuses on the order of +20 which lets them do some pretty ludicrous things but they have to be pretty high level to manage that. Impossible difficulty is 20 and ludicrous is 25 for reference. My current design keeps people bounded pretty close to reality but maybe I should change it so that they can do things way beyond what real people could hope to accomplish. In any case it isn't a martial vs. caster thing in HBT because everybody can do Rituals if they want to but it is an interesting idea to chew on.