My download took 16 minutes (28 meg down cable)
If this is your 1st time in AHIII or beta, go to options> graphic detail and check all DISABLE boxes and turn all slider options low detail/miles. Once your baseline frame rate is determined, add back as much as you can, keeping the FR playable.
Hitech used an Nvidea 9800GTX card to develop/debug so unless your card is WAY old, it should run reasonably well for you. I'm getting 55 - 59 FR with a GF 960GTX 2 GB card.
The graphics are STUNNING, especially on the ground, in terms of detail. <S> HTC for the many, many months of hard work!!