Soft you left out a part of the Talents description, and it might not matter to some when making this decision.
Dastardly Strike: Whenever you make a successful attack against an opponent that is denied its Dexterity bonus to Reflex Defense, the target moves -1 step along the condition track (see Conditions, page 148).
Nothing about this in the FaQ either which has errata/clarifications in it for the core.
Myself, I would give it to you if you hit the Target's Ref Def or beat it and the target is somehow denied their dex bonus and do at least one point of damage. You spent a Talent for this and it is worded how it is worded so. Plus you have an extra stipulation to get the CT movement plus me wanting you to actually hit a Ref Def not the DC 10. I looked through Ref Def, Attacks, and Autofire for discrepancies on defining successful attacks, Ref Def being hit core pg 145, and Autofire. It does say on autofire
Autofire is treated as an area attack (see Area Attack, page 155). You target a 2-square-by-2-square area, make a single attack roll at a -5 penalty, and compare the result to the Reflex Defense of every creature in the area. Creatures you hit take full damage, and creatures you miss take half damage.
So that is why I would say you have to hit the Ref Def for me to consider it a Successful Attack.
There is a whole post on here with a list on Talents/Feats/Powers that let you deny Dex to a target, so need to go into them I would think. And in my games I treat Flat-footed/surprise/denid Dex mod as such.......
House rule
"If unaware of an attack, or if surprised, or not allowed to add your Dex Mod to your Ref Def it is treated like Flat-footed and vice versa. And can be used interchangeable for triggers for Feats, Talents, and Force Powers."
And this would be a little more powerful due to that. I am ok with that, but you the PC's best be ok with it too. Because something like this will get used to against you once in a while too. And you must see the potential for power of this Soft, because you posted it on here to help qualify being able to use it or not. So something like this I would stress to the other PC's playing in the game.
"Do you really want PC1 to have this if it will be used against you every so often? One terribly timed nat 20 from a NPC who gets a good Initiative roll and a couple of other select Feats and Talents stacked onto this too. And the way I make all the PC's start in a small area at the beginning of an encounter? You are looking at 1 to 3 CT movement to maybe everyone in the first round of combat."
I am ok with it because of the above circumstance it will make any encounter very challenging. Easy way to put all the PC's down one or two or even three down on the Condition track and turn it into an edge of the seat fight for their lives. But I bet one or two of my friends and PC's would want to talk it over with the person wanting to do this combo.