The Newbie DM had a great post over on his site about using powers in 4th edition D&D and how you shouldn't let them straight jacket you into a particular way of describing your moves. (Wow, that is a long link) The post, which you should read, brings up thoughts of some stuff I've talked about before - albeit briefly - here, and in much greater depth with people in the really real world. That stuff? Simply put is divorcing your game mechanics from your narrative.
What Newbie DM is talking about, or what his main point seems to be, is that you don't need to be contained by the description provided to you by the system, provided that you are consistent with the mechanical side of things. To use the example he uses, who cares if you describe yourself as sweeping the legs out from under your opponent, or hit him so hard he falls over onto the ground, provided that the mechanics are the same. In this instance, he/she took damage from your weapon, and ended up on the ground prone. Everything else is just gravy right?
I have to say that I agree with Newbie DM on this one. Narrative is where the player has a chance to make their character shine. Mechanics is where the GM has the chance to keep it all making sense and judge challenge. So who cares if a missed hit is described as bouncing off your armor, being parried with your sword, or completely avoided with a back handspring? (Assuming, of course, that these descriptions are otherwise appropriate and don't break the feel of the game/world)
Fact of the matter is, mechanics make people fairly generic. Especially as designers streamline systems more and more for ease of play. It is a sad fact that mechanically, aside from a few traits/talents, there is very little difference between my housemate's noble priest and my Sister of Battle in the Dark Heresy game we're in. Nor is there much difference between my Sister of Battle and the other Sister of Battle. Mechanically the characters are very similar, perhaps not blindingly so, but still similar. In play though, the characters couldn't be more different. The reason for this includes what we've equipped ourselves with, sure, but most importantly the difference comes from how we play our characters.
In M.A/C.C in the player section I talk about this as well. In one of the play test campaigns the three players ended up with very similar characters mechanically, and once again - through play - they could not have been more different. Similar capabilities, but how they handled things - even when employing the same mechanics - was completely different. Different enough that I never realized how close they were until I looked at all three sheets after the game was over.
Now, don't get me wrong, I am not saying that mechanical diversity is bad or wrong, I am simply saying that it is hard to be unique through mechanics, and that it is getting harder with every year it seems. The bigger the game, the more likely there is going to be someone who is built very similarly to you mechanically. So why not break free with your description? Keep the game world and feel in mind, but play it up. If one person is describing themselves and diving behind cover, rolling back to their feet, and shooting their gun, then describe your character as standing stock still and letting their armor absorb the blows while they return fire.
If things really need to be sorted out, the GM can pause the game and handle the mechanics. That is their job. While it is going along though, your job is to help bring your characters to life and have fun. So, why not have fun with it?