I have been a long time XP user, mostly because I have been a Mac user for 30 years.  I had some limited experience with FS in the early 90's. I started with iFly in the early 90's. Then I went to lunch one day with Apple's Mac desktop engineering manager at the time - my job meant I collaborated extensively with all of Apple's hardware engineering groups from 1991-2006 - I told him I started diving into flight sim and it turned out he also was an avid flight simmer. He suggested XP. I bought XP and have loved it ever since. Having said that, I do at times think about switching to  PC gaming hardware with high end graphics at a reasonable price.  Even though I have an iMac with 2G Vram there are times when frame rate still becomes an issue.  I have researched P3D and it looks appealing but I am very happy with what I have. The only drawback I see with XP is that Laminar seems to put most of its dev resources into the GA planes.  Like someone else here noted, if you fly GA then XP is superior.  If you fly jetliners like I do then the XP 11 planes have gotten better---not great--but still very enjoyable.  The "Zibo modified" 737 is excellent...and is free! Much better than the FF767 in my opinion.  As for XSB, about 75% of my flying is on VATSIM and XSB is very adequate.  I bought SkyMax Pro add-on and think it is overrated.  Just OK imo.  I have all of Mister-X airport scenery - LAX,BOS,SFO,etc. - and his airport scenery is by far superior.  So, the only issue I see with XP is that in order to keep up with the software development in the XP world I am looking at making a Mac hardware upgrade. If I want graphics capability to carry me forward for many years to come, unfortunately,  it will be at significant cost.