If the FS is running while your doing your test it probably more of 500g-190g=what the sim is using.
But the reality of it all is that Most if not all providers only guarantee you that speed to the 1st hop of the connect, after that all bets are off.
So for all you know they could be feeding everyone a 500g connection but only connecting to the backbone at 200g. The only way to tell for sure is to shut all programs using the net, and then run a traceroute to the server that your game connects to, and then watch and see where the bottlenecks are.
It could be your provider having a crappy connection, it could be the MS servers are overloaded, or it could be something in between the two of those causing problems.