My computer was middle-of-the road when I got it three years ago. When I started playing Aces High a little over 2 years ago it ran the game at a pretty decent clip. Some months later I wanted to try skinning, so I had to get the Hi-Res pack. I decided, hey I'll just run it in game on high res. So, after turning down some of the other settings i was able to get pretty decent frame rates with it- in the 40's 50's most of the time. My computer wasn't displaying some stuff correctly, though (that and I couldn't play other games) so about a year and a half ago I got an NVIDIA 8600GT, which even at the time was a middle of the road graphics card (it wasn't even one of NVIDIA's 'gaming' cards), which was about $150 ish at the time (you can get one off of NewEgg for like $60-$70 now). At this point I was able to turn all of the settings all of the way up and play the game at 50-60 FPS at 1280x1024 res. A little later I also bought another gig of RAM for my computer, which was at the time running one gig. Not because I needed it, but because it was on sale for $30.
That's about my current rig, which at current prices for electronics would run about $100 in upgrades. Right now I run Aces High II at 1024 res, with the detail sliders all of the way up, I think 8x AA in the NVIDIA control panel, though I'd have to check, on a 1680x1050 monitor, with TIR and usually iTunes and FireFox, and around 50-60 other processes (lol) running in the background. With all of this I get 60 FPS normally and usually around 30 when we launch during FSO. I almost always run smooth except in the largest battles on the really taxing maps.
I do NOT have a sweet computer. Actually, I get ragged on because of this thing (case wise, my monitor makes up for it for the most part, though

). But I can still get everything there is to get out of Aces High.