I think I'd answer slightly differently, though somewhat along the same lines.
Austria's advantage is TEMPO
France's advantage is POSITIONING
What do I mean? Well, here goes...
First of all, this format is very very very much centered around the MSL (main stalemate line), or Versailles Line, or whatever you call it (side note: Germany vs Italy, another popular version, is centered around the Juggernaut line, but that's a whole other discussion)
There are plenty of articles that discuss that line, but I'd say this is a good one:
http://uk.diplom.org/pouch/Zine/S2001M/ ... Draws.htmlEssentially, the line splits the board into two groupings: the north/west power (France here) has STP (st petersburg), BER (berlin), MUN (Munich), MAR (Marseilles), SPA (Spain) and everything north/west of those
The south/east power (Austria here) has MOS (Moscow), WAR (Warsaw), VEN (Venice), ROM (Rome), TUN (Tunis), and everything south/east of those
In order to get to 18+, one power must take and hold (long enough to get to 18) at least one center across the stalemate line. And here's where it gets interesting. The easiest opposing center (by far) to take is St. Petersburg, since Austria can get there in four moves from Budapest or Vienna, and in multiple paths; while France can only get there in four specific moves using its F Brest build, and critically, France must bypass London in order to get there in four moves.
This means that St Petersburg is VERY easy for Austria to take. HOWEVER, it is IMPOSSIBLE for Austria to hold STP against a concerted assault by France (you simply cannot hold this center indefinitely against a focused naval assault, that's just how the board is constructed)
Comparatively, Tunis is a bit of a pain for France to take (he can't get there until 1903, and usually it's more like 1904-5, and by then it requires some effort), but it is VERY easy for France to hold Tunis once taken (F GOL/WMED/TUN is a nearly impossible line to break, and if you can get into Piedmont it becomes fully impossible to break)
So basically, Austria has the quickest path to 18 (break into STP, and hold it just long enough to pick up all of its natural centers), but if Austria is stymied (if France takes Tunis and holds Berlin/Munich, for instance) then France can just (sometimes slowly) force his way to 18 centers. This is also further compounded by the fact that Austria, as more of a central power, has more places that are easy to get to to build without going too far out of the way, while France has fewer such centers. So not only does Austria have a potentially faster path to 18 than France, Austria can also (sometimes) spam out more builds than France, and potentially overwhelm the board that way.
So Austria is the aggressor power, and in fact must be aggressive to win.
France, meanwhile, is in a situation where if he can survive the onslaught, has a very very strong natural advantage over the long term; for instance, if the game was played to 1920, and it wasn't won the first time someone hit 18, then France would be a natural favorite. It is relatively easy for France to take and hold all of his natural centers (Austria can contest Germany, but if France puts sufficient resources into German centers, he can force the issue there), and Tunis is a target that can be taken and held against all opposition unless Austria really focuses efforts on fleet building and/or just overall forces in the Italian theater.
So France is the defensive/reactive power, and must successfully counter Austria's aggression to win.
PS I'm personally better as Austria, but I've gotten my ass handed to me a number of times as Austria, and I've won a pretty good % of my games as France.