It arrives on Thursday!
Umm... FSX isn't necessarily poorly coded, but the timing of the release was horrid. Microsoft's "ACES" team which handles it deigned the game for single core processors because somehow MICROSOFT was unable to predict in 2006 that multi-core CPU's were going to be the future of computing. This is largely baffling though since the game uses so little video resources with so much available? If I run my gpu in SLi mode, my framerates go down because the game gets confused and uses more processing power to try and figure out how to allocate the scenery and such... it's weird.
On my current system I run at good frames (25-80 fps) depending on where I am and in major cities or major airports it drops into the low tens or high single digits. With the new system... I anticipate being able to run it smoothly all around and that (for a real pilot) is worth its weight in gold. People are always surprised that I even play FSX actually and spend so much on my system to make it run, but in actuality... when I'm paying $5/minute for my flight time in the real world, it pays dividends to blow $600 on updating your computer to have a better understanding of your flights.
I have x-plane as well. I think x-plane is super cool and if I were going to recommend one for someone who had never really used either, I'd say x-plane for serious pilots or someone after a simulation. The game is infinitely smoother, the flight characteristics imo are more realistically modelled, and you get some unique stock aircraft. That all said, the reason x-plane runs smoother is because it doesn't load oodles of visuals initially as FSX does. In fact, it doesn't even load an entire "earth", it simply loads the area you're in and the rest is ocean until you install it and select for it to be used.
Both FSX and X-plane are approved by the FAA to use as "flight training devices" (a "Flight simulator" has to move speaking generally), but the only people I know that have ever used FSX for flight training was the US Navy, and I don't know to what degree. X-plane is what we use in our FTD's, albeit an older version.
If you really want to get into the nerd of it, FSX tries to simulate what the performance charts for the aircraft say will happen for given conditions, whereas in X-plane they attempt to simulate the earth (and mars (COOL!)). By that I mean, x-plane actually "builds" an environment with "real" fluidlike air and then says this propelled is what is moving that air, and this wing is what's flying through this air, and then it tries to replicate how that would happen. This is why, bar none, x-plane is a better sim. Because they thought like God (or whoever) whereas Microsoft thought like Microsoft.
Anyways... I'll update once I get things sorted (prolly this weekend). It should be 2x the horsepower at stock speeds since I'm adding 2 cores and they're both (my old and new) roughly in the 2.8ghz range.
