This has been a really interesting discussion centering on the paradox that grappling (particularly with Pin, particularly with grapple-optimized characters) is both "not cool enough" (because you get to act fewer times) and "overpowered" (because a specialist can reliably shut down a non-specialist).
There have been a lot of very good comments here, so I'm going to reply to some as they strike me and hopefully correctly attribute them to the right person. I'll preface this with saying I haven't had a player twink-out a grappling specialist, so much of my observation is based on how it functions between non-specialists and then more abstracted cases.
I DO see the case being made for making Grapple based on Unarmed Attack rather than Athletics (though as I commented previously, I would expect a logical follow-on ability similar to the Eagle Eye trick allowing you to substitute your Athletics (Str) bonus for your Unarmed Attack bonus X number of times per combat).
Cinematically, I'm ok with the initial grapple being a full-round action -- there's a lot of action happening within a single die roll there, and I would gently disagree with Sletchman(?) in that just because it's slower-developing than your standard 2 half attack actions doesn't make it inherently more boring.
Particularly, want to point out comments by two of the newer members:
I think it was Takeru who essentially suggested the addition of a Grab condition -- I could see this being a useful addition, as Grab - Held - Pinned allows you to rebin some of the Grapple Benefits, there are some Benefits that make sense to only require a preexisting Grab rather than a full Hold.
Wireless suggested making the Grapple defense/escape (on the Held character's turn) a Half action -- I could see that working, maybe even along the lines of Half Action if successful, Full Action if fail (which would help inspire Action Dice used to escape, since a success would leave you a Half Action to move away or otherwise escape being immediately re-grappled.
In conjunction w/ Takeru's suggestion mentioned above, I could see the initial grapple check resulting in a Grab condition, with the defender on their turn choosing to either attempt to escape the Grab (via the opposed Athletics/Grapple roll, possibly allowing for substitution of Acrobatics, etc) OR choose to do something else (possibly requiring a Concentration check) and becoming Held at the end of their action -- I see this described cinematically as someone being grappled by guards but rather than attempting to fight off the grapple, they choose to forgo resisting the grapple to get off a last desperation thrown dagger (etc).
I imagine a revised sequence could look like (again, this is not a reflection of how things currently work but one possible way it COULD work):
Round 1, Init 19) On his initiative count, McAwesomepants: initiatives grapple vs Gobby 1 (Full Action) and wins the initial opposed Athletics check. (Gobby 1 is now Grabbed and, unless he succeeds with an opposed Grapple check to resist/escape on his action, will become Held)
Round 1, Init 9) Gobby 1 chooses to either contest the Grapple with an opposed check OR attempt some other action and voluntarily fail the opposed Grapple check without rolling (becoming Held at the end of his action)
--> On a successful opposed Grapple check to escape, Gobby 1 breaks the Grab and has a half action remaining (to attack, move away, etc) / on failure, the Grab becomes a full Held condition. Alternately, Gobby 1 takes some other action and automatically becomes Held at the end of his action.
In keeping an emphasis on cinematics, after adding Grab to the sequence (Grab-Held-Pinned), adding the ability to apply additional Grapple Benefits per AD spent on a Critical (rather than the flat 2 benefits from Spycraft 2.0), this would mean that on a Critical initial grapple, a single AD would result in the Grapple target being Grabbed + Held, 2 AD might allow Grabbed + Held + Pinned in a single action, or Grabbed + Held + Throw -- I see this making things flow better and making Critical Successes feel just that much more awesome.
This would also be a point to potentially integrate one of MA's major concerns, ie allow special characters to spend AD to cancel some Grapple Benefits (perhaps on a 1:1 basis vs Standard Characters, 2:1 basis vs Special Characters)
Just some thoughts from my end of the asylum...