PC is unlikely to be able to run that program at acceptable frame rates even at the lowest settings and I know that my PC is significantly more powerful than many other player's PCs. It is fine to limit your market to people with high end gaming PCs when your target audience is large enough, but that is not the case for non-arcade combat flight sims.
For 12 years I've listened to the reasoning of the 100mb limit and to keep graphics limited due to player PC specs. I would love to know the real stats of average player PC specs. I would bet (curve over the years) the majority are using systems on average of 2 years old, which are more then capable of running sims at high or ultra high settings like the P51 screenshot.
You don't need a mega gaming rig to play sims at high levels, I just built a new micro atx system for $1,100 NZD (would be far less in US prob about $800) including a radeon 8550 and it runs everything maxed out fine including FSX and other sims. Even the $600 laptop I just had could run AH with all sliders maxed out.
The 100mb limit at (majority of our players have 10 year old PCs) has been an excuse that's gone on long enough. Real reason is that they don't want to spend the time and $ developing a new graphics/physics engine and trying to milk the existing engine for as long as they can. This engine must of been first developed in late 90s, even AH2 didn't look any different and hasn't really changed that much since except for new extra effects,objects and textures.
AH was dated in 2003, now it looks like something I can play on my Galaxy Note 2.

Thankfully only thing that has kept it going for me when I return every now and then is the odd good furball, but they are becoming less and less with the horde mentality.
I'd hate to see AH go but they seriously need to look at releasing a new version. Otherwise even the small number of hardcore simmers with 10 year old computers and looking for something to play on them won't be enough to keep it going.
<S>...-Gixer