I get decent frames on Stratis, 50-90 FPS most of the time, but on Altis I see between 5-25. My system specs are as follows:

MSI Z77 Mpower
Intel Core i7-2600K at 4.2 GHz
16 GB DDR3 RAM
2x 1TB WD Black
MSI GTX680OC @ 1.2 GHz 4GB RAM

My CPU usage does not top 30% on Altis, but will be as high as 50% occasionally on Stratis on Core 1. My RAM usage is the same on both maps, less than 1.5 GB, which seems wrong considering the explanation of resource usage on the latest SITREP. GPU usage is consistently under 50% on Altis, usually 90%+ on Stratis. The numbers on Altis get much worse with even one AI present, and quickly drop to the 10 FPS range with 10+ AI present. Frames are much worse near cities/towns/villages as well.

My visual settings are not excessive, either, at least for a system spec'd as mine. Object draw is under 2k, shadows at 150m.