It was written somewhere that the incremental improvements added by the 2.06 patch did as much to 2.0 as BoB2 did to BoB. I think it was in the same simhq review that JScones linked to.
My personal experience with 2.06 and higher is that this might not be the stablest game I have ever seen, but I can not remember more than 2 or 3 major crashes since I had it, which imo is absolutely ok for such a complex program.
XabbaRus I am (still) playing on a 3200XP, 1 GB, GF6800, everything somewhat overclocked, with most on high and the only time I get slowdowns is when there are hundreds of planes in the air.
It was written somewhere that you should not set horizon detail higher than medium with such a machine, because it is a very costly option.