For me the performance is great, hardly any stutters or crashes and I have 60 hours in my Logbook now. There are some bugs and issues so that are not Xbox specific and also occur with the PC Version. For me the most annoying ones are;
Autopilot turning back to last waypoint when selecting an approach in flight.
Issues with textures at some airports. (Floating roofs etc…)
Get back to your assigned altitude bug in ATC (Should be fixed with WU6)