I do like to potter around in Flight sim X occasionaly I also have the acceleration expansion pack. Pretty good package for the money. It is however very resource hungry and you'll need a high spec PC to get the best out of it. I have all the variables (Traffic/realism etc) set to Max and my new super PC handles it with ease.
Max Traffic is a bugga at LHR, had to taxi for 15mins then wait another 20mins for take off clearance last week
now that's 'realism'!