What do you mean by "performance"? The real world aircraft performance? Assuming you are talking about the sim, it is modeled extremely close to the real thing. 90% realistic systems or something. I have completed many flights in the aircraft, a very enjoyable experience. Not a real pilot or T7 expert, but it's safe to say that this is the most realistic aircraft in terms of systems. Fuel burns accurately, climb perf is well modeled. The FMC will calculate if the route is long enough to reach the cruise alt for over 10 minutes, and will calculate if the weight of the aircraft is light enough to reach it. Step climbs are included, if the selected SID requires it (or you can manually enter).