As  I said I have not seen any of the problems exibited by other users with sound issues or any other problems. What you have to consider is that FSX is the basic product and everybody's set up is quite different from any other persons, by the aircraft they have installed, scenery, FSUIPC, etc. I know they should all run in harmony but I know they do not always work that way.

I have spent many hours tweaking a friends system to run the most basic of addon aircraft packages, that run perfectly on my system. This system has every available UK scenery package from Horizon, global terrain, and all UK airports as well as Weapons and a whole lot more.
There are many possible resources all running at once and any one may conflict with any other. No amount of Beta testing can cover every combination of PC or set up that is out there.

On my PC I run FSX acceleration and a few addon aircraft, one package of Horizon airports as well as the scenery and models that I build, perhaps thats why I have no problems with only a minimal system? It may be interesting to find out how many people having problems are running just FSX or if they have the Acceleration package installed for example, or perhaps what other packages they do have loaded.

However, I still think it is worth buying.