They ruined the rogue. Before, the rogue was boring. He was not, however, underpowered. Now the rogue is just garbage. It is nothing but a strictly inferior fighter. It gets worse weapon choices. It gets worse armor choices. It gets one less maneuver. It has less hit points. It does not gain an extra attack at sixth level. When it sneak attacks, it deals far less damage than it did in the last playtest packet. In fact, sneak attack is now nothing but an inferior deadly strike. So, the rogue is hands down an inferior combatant.
It also lost some of its advantage when it comes to skills. I mean, I would call its skill mastery maneuver largely a wash, in terms of power, for what it used to get. Using skills won’t be as much of a sure thing, but its maximum rolls went up as well. And, a rogue will get 8 trained skills now. Thing is, they hacked up the skill list into super specialized options ala 3e again. So, those 8 trained skills amount to fewer overall abilities than its 6 skills did last time around. In fact, it is now fairly hard to build a character who is good at any decent number of skill based abilities unless you play a rogue. So, this change nerfed everyone. You even need two skills to be perceptive (listen and spot) again! Lame. Very lame.
I like the idea of rogues getting expertise dice. But, the overall implementation of the concept, and the changes that the rogue has gone through, leave a lot to be desired…
This is how I would fix the class:
1) Rename "Sneak Attack" to "Dirty Fighting." Add the following feature to "Dirty Fighting:" any foe that takes damage from "Dirty Fighting" grants advantage against all attacks made to hit it until the start of the rogue's next turn. Please notice, this is designed to aid a rogue's allies. The rogue would not get advantage against this foe. At best, if a rogue was dual wielding it could lose disadvantage with its second attack. So, by itself, the rogue will not be any better at dealing damage from levels 1-4 than it is now. It will, however, up the party's DPR by giving its allies advantage to hit whatever it has just hit. It will make the rogue feel like a sneaky bugger, but it won't make the rogue feel like an assassin (as he will still be dealing the same damage as the fighter but worse).
2) Remove the "Skill Mastery" maneuver. Give all rogues "Dirty Fighting" instead.
3) Give all rogues a class trait called "Skill Mastery." Skill Mastery allows rogues to roll twice for all skill checks and keep the best result. When a rogue has advantage on a skill check, it may roll 3d20 and keep the best result. Allow rogues to gain bonuses to skill checks (from rogue levels) at 4 times the speed of other classes (the maximum bonus a rogue can get in any single skill from training is still +7, though). This would mean that instead of being able to max out only one single skill by level 10, it could max out 4 skills. At level 20 it could max out 8 skills.
4) Allow rogues to gain manoeuvres at the same rate as fighters.
5) Give a rogue more manoeuvres designed to debuff its targets and to grant itself advantage (against targets) with skill checks.
6) Boost a rogues HD to d8.
7) This is a big one: At 6th level a rogue needs something to keep it competitive with the fighter (as a result of the fighter's second attack). So far, this is the best idea I have seen--give the rogue "Backstab." Backstab: when a rogue makes an attack roll with advantage, if it hits with both attack dice it deals a critical hit. If you combine that with the ability to get advantage about 2 out of every 5 rounds or so, via the new manoeuvres, the rogue will be able to deal meaningful damage (in big spikes) without having a higher DPR than the fighter.
8) Finally, right now the rogue has no real reason to choose to use sneaky weapons like the dagger, shortsword, or the like. There are other finesse weapons which are just better. This power is designed to add some flavor for the "I want to sneak up and cut some throats at level 1" crowd. At 1st level, give the rogue a class feature called "Sneak Attack." Sneak Attack: when you attack a target that grant grants advantage, if your attack is dealt with a dagger all of your "Dirty Fighting" damage dice are maximised. The damage per round bonus from this power will be minimal, as you are forced to use a dagger, and the benefit of this power does not stack with rolling a critical hit. This power is really just for flavor.
With these changes a rogue will deal about 80% of a fighter's damage per round, but in spikes. A rogue will maintain its skill based identity, and will actually feel like it can use skills in combat without ruining its affectivity. The rogue will be fun!