Either love it or hate it, F1 2010 is a good opening game for the XBOX series, any F1 fans will love, others may
Many racing game fans may not approve of it becuase it's far from a Forza..
I am yet to try online for more than an hour, but from what i've experienced, it's fun.
Career mode is 19 seasons long, after each season you'll recieve new contract offers depending on your performance (eg a good performance could land you a spot with Ferrari, Mercedes, Redbull or McLaren where as a less impressive season could mean you end up with Lotus, HRT or Toro Rosso)
The career mode should most probably be started on an easier difficulty for the first few races but once you're used to it, try turning off some assists or AI driver level up to Professional or Legend. When competing on the harder difficulties it's impossible to get bored because rivalries and in race duels are so intense!
Overall, F1 2010 is a great game for ANY F1 fan.
I would reccomend it to many other racing game fans but some may not like it, this is why you may be better off renting it first.
One thing's for sure, you'll have a lot of fun!!