Okay, so I have played the game for maybe an hour or so total of actual flight. I can say that this game is great but is lacking some of the features of Flight Simulator X.
On the one hand, it performs much better on higher graphical setting than does FSX. Generally it looks much better as well and doesn't take up nearly the same amount of space on my computer. Everything looks great. I like how easy the interface is to use and the new features (UI in-flight, the free flight map, etc.) are fantastic. I also love the Xbox Live integration.
On the other hand...
-No slew mode
-No fast aircraft available yet
-Unskippable first mission or two with that annoying woman
And, worst of all, only TWO planes come with the game (I have a Live account) and any additional content being offered costs a significant amount of money. With the amount of content inevitably to be released, nobody will be able to realize their capacity to have anything approaching a "full" game without spending at least $50 for even 3 or so add ons. I find this to be absolutely ridiculous. Sure, the game is free, but paying close to $20 for every single aircraft released to expand my hanger is not feasible.
That being said, with the addition of user content I'm hoping the game will be more pleasurable. Hopefully the island(s) of Hawaii won't get old too fast since what is included looks better than FSX, but shit man. I like the game but I am afraid it will cost too much to make it truly worth it or fun. Plus, without slew mode, the game will drag HORRIBLY on without the addition of faster aircraft I can just cruise around in.
It has a lot of polishing and, with the addition of some of the more practical options offered in the traditional Flight Simulator series, Flight can be a great game. Microsoft just needs to think more of its fans and consumers and how much we are willing to/able to afford in order to improve the game on an individual basis.