As for the mechanics, I think this is a great improvement over CT, which was improved on by MT's task-based system.
Hmm. Characters are exploring an old ruin they found on a forest moon of a gas giant where they skimmed fuel. There is a spider-like creature hidden in its web over the archway of the entry to the ruin. As the PCs pass under, the Ref would like to do a quick check to see if any of the PCs notice the spider-analog before it drops down on upon one of them.
At the same time, the Ref wants to keep the mystery alive and not alert the players that there may be danger ahead (other than what they already expect). And, the Ref doesn't want the players knowing how well their perception checks went.
In CT and MT, this is quite easy. The Ref throws 2D, adds in a point or three for the DM, and he's done. He rolls behind the screen. The players don't know anything about the throw--only what the Ref tells them. And, the DMs are easy to remember. There will be only a couple--maybe a skill, but most likely a modifier for INT or WIS. I found these easy to memorize as a campaign wore on, but in the beginning, I'd write down a few common checks for the PCs so that I could do this type of thing behind the screen. There are lots of instances where the Ref wants to know if a character notices something but doesn't want the players to know squat about the roll.
This really isn't near as easy with the T5 task system. It's a lot more fussy. Even if the Ref writes down Stat + Skill target numbers for things like a perception check, the players still can get an idea of the difficulty because they can hear if the dice is a few or many.
This is do-able, but just a lot more fussy. Adding a +2 modifier to the result of 2D is a lot faster and easier than having to add up the result of 4D and compare them to a target.
Then, there are times where the Ref wants the player to roll but not know the result of his throw. This happens a lot when the character is sneaking around. The player should roll the sneak attempt for his character, but he shouldn't have too much of an idea of how hard it is to sneak around.
With CT or MT, the Ref can simply keep the target number secret. When a character wants to sneak from point A to point B, and the Ref knows that there are concealed cameras in the area that will probably pick up the sneaking character, he'll make the target hard. The player rolls normally: 2D + skill and mods, but he has no idea what the difficulty is.
Again, with this T5, this process becomes a lot harder to pull off. It becomes more fussy. The Ref can roll have the character's dice secretly behind the screen. Or, the player can roll all the dice, where the Ref has a secret modifier to the throw that he 's not telling the player. Or, the Flux can be used (Uncertainty Dice). All of which are a lot more fussy than the CT or MT methods.
And, the player still gets a good idea of the difficulty of the sneak throw, because he knows how many dice were thrown.
In the case of the example above, the player sees the sneak task is a lot more difficult and reasons to himself, "Hmm...this shouldn't be this hard. There must be hidden surveillance devices...."
Giving the player information that he shouldn't have.
So....no, I can't agree with your statement that the T5 mechanics are an improvement over those used in CT or MT.
In fact, many think the T5 task system is inferior to what has come before.
Really, look at how efficient the mechanics are for personal combat (which I've yet to really test, but in a session or two we'll be there).
They read good on the surface. When you dig into them, you'll see the problems.