Another supporter of the game's atmosphere here: Shadowrun's "feel" is very well developed, and an absolutely fascinating environment to experience as player and game master alike.
I only ever played the 1st edition, and the rules could get a little cumbersome, especially in combat, where I seem to recall thirty minutes of game time to resolve a few rounds of gunfire (although some 3E combat rounds go that long, too). Shadowrun did do a good job of making firearms extremely deadly, which many who come to the game from a h.p.-based background might find somewhat disorienting (especially since creating a character took a while, too - got $400,000 to spend? Well, there's a lot of stuff to buy: cyberware, equipment, vehicles, contacts, bus pass, etc.)
Anyway, a very fun setting, and a nice change of pace from swords and chainmail (though, technically, there were swords available in Shadowrun, and a friend of mine played a Troll with a battle axe who quite simply mowed through the opposition). I don't really have any complaints about the dice system, and the detail that went into the setting was terrific. It was hard for the game master to deal with a decker while the rest of the group was trading bullets with the bad guys: gotta keep switching scenes.
One complaint: the novels. Ugh. Well, o.k., I only read one, called _Never Deal With A Dragon_ and it was terrible.
Enjoy the game.
Warrior Poet