Wow, so much to say, so many opinions, so little good it will do....
There was a thread about a month back that asked about the perfect system and I pretty much showed that a 'perfect' system doesn't exist, because you either sacrifice time for realism or fun for function (kind of an x - y axis circle graph. (yeah get out your trig functions folks)).
I can say for certain that no amount of realism injected into a game will equally cause the game to stall during combat. Likewise no amount of function in a game will equate to fun.
For example, you as a DM want to run a historical campaign that mirrors the events of Medieval Europe, with certain elements of fantasy introduced. You come up with a system and you gather some players. One of the players wants to play and elvish ranger (having just seen the second installment of the LotR movies) and can't wait to take a Feat in Shield Surfing so he can pull off that move from the Helm's Deep battle. Obviously there is going to be a disconnect - Real world physics say that that stunt cannot be performed during that time period for several reasons, Architecture was too irregular, shields of that period in Europe were all curved to deflect blows, the arm straps of the shield would be in the wrong location and surfing had not yet been invented. So the DM get his realism and the player gets to frown at having to perform Medieval flanking movements in battle.
OR
The DM wants a quick battle system that takes less time away from his dramatic story-telling so he implements fast rules. Meanwhile one of his players has been dying to use a new system that recreates real physical trauma on the damage dished out by his historically accurate portrayal of his Duetsche Zwei-hander. The DM looks over the rules and realizes that the cross checking of the charts is going to take the steam right out of that quick combat and vetoes it, at the next session the other players complain and the DM relents, therefore slowing down combat. The players are ecstatic and the DM wonders if there are any good books he can read during the combat sequences.
Obviously both of the scenarios are hyperbole, but the do illustrate the point; you can't have all of the greatness in one system, you have to move along the axises and the best you can hope for is mediocrity.
That's not to say that some DMs can't fake it one way or another, or that some rules cannot be changed to move it in a direct more suitable to what you need, but frankly, its FANTASY. I don't care how much you train, a Chinese Kung-Fu artist cannot fly through the air kicking multiple opponents over a half mile line of flight (ala the latest batch of martial arts movies) and though great for a special effect sequence, surfing a shield is both stupid and impractical and shooting a very thick rope with a single arrow isn't going to make it cut in half (Newton, Hawking and whole host of other physicists would like to explain how that works in real life.) Sure there are accounts of people falling hundreds and thousands of feet and surviving, but there are more accounts of people falling 10 feet or less and snapping their necks. It just isn't heroic.
Yes, 4E is probably less 'realistic' than 3.X, but 3.X was less 'realistic' than 2AD&D, and so on and so on...But the real question is, is it more fun? Frankly, I don't know the answer to this, I haven't played enough to know yet. But at the same time, I know what I like and what I don't. I have seriously thought about scraping my 3.5 game because there are far too many 'cool' rules in them. YMMV and to each their own, really, does any of it matter?