1. I played it about an hour or two a day for two weeks, so maybe 20 hours or so at least.
2. Just flying a ship is exciting in itself, from taking off from a carrier, to just fiddling around with all the controls, and eventually docking with a carrier after doing a mission... then you get to engaging in dogfights, which is the best bit. It's immensely satisfying to play, but it can get very tricky in some missions. Probably best you get a joystick, if you don't already have one, for the best experience.
I'd also like to put these games out there if you haven't heard of them for some reason: S.T.A.L.K.E.R.: Lost Alpha, The Dark Mod (for fans of the Thief series), and UFO: Alien Invasion. The last one is very much like XCOM. Really good stuff once you get into it.
http://www.moddb.com/mods/lost-alpha (the main website is down right now)
http://www.thedarkmod.com/main/
http://ufoai.org/wiki/News