I prefer marks for the variety and options they bring, but I like that the game has both since auras are better for some other player's styles.
I have now played a str/wis paladin, arena fighter, wildblood warden, and hybrid swordmage/ barbarian and liked how I could defend in different ways with each one of them. I have never found the mark mechanic that complicated or too much work. The one possible exception was when my paladin was in the same party as a fighter since we had occasional times where we both wanted to mark the same enemy, but I think it would have been worse if we both had auras.
I prefer to have both in a party. A group of 6 PCs with two defenders, one mark-based, one aura-based, is pretty effective and hard to break through the line.
Personally I've never played aura defenders, but I've been wanting to play a Berserker for a while, so it's a draw.
"Not only are you wrong, but I even created an Excel spreadsheet to show you how wrong you are." --James Wyatt, May 2006
Having played both a Fighter and a Knight, I'll never go back to the Fighter. It's true that marks have more versatility, and Fighters get more ways to position enemies, but I'm more than willing to trade all that than have to develop precognition to know when and how to use my immediate action each turn. Do I punish this guy? Or wait and see if someone else is going to twitch? Should I use my defensive utility this turn?
The whole business drove me insane, especially at higher levels. Defending with a Knight hasn't been a problem for me to date, keeping enemies from getting away is ridiculously easy with defend the line/vicious advantage/world serpent's grasp/glowering threat/hammer strike/takedown strike (yes, I commited the sin of not taking Guardian for my Knight). If anything, my problem is that I'm too sticky for my own good.
What does surprise me, however, is how aura defenders seem to confuse and annoy DM's. I went to a convention to play LFR a few months back, and at every table, it was the same. The DM would constantly provoke battle guardian, and seemed quite irritated when I pointed out I had an attack, despite explaining the mechanic several times. Finally they just attacked me with everything in an effort to kill me, even with creatures I had no way to lock down at all!
It gets really bad when I fight Skirmishers. The DM will have the creature attack, then shift away (because, you know, if the monster gets a free shift, they apparently feel they MUST use it), only to have their beastie knocked on it's behind or immobilized (courtesy of Power Strike+Weapon Specialization) and the game grinds to a halt as I explain (again!) how I did that.
Then they'll do the same thing with another Skirmisher, I'll reply in kind, and we'll get a 20 minute tirade about how "opportunity punishment is ridiculous".
"You can always judge a man by the quality of his enemies." -The Doctor, Remembrance of the Daleks
I love my swordmage. He would not be able to function the same way without marks. Therefore if I had to choose one or the other, I'd choose marks. Nothing really wrong with auras, they just all play the same way.
I loved the way my cavalier worked, defending with marks, auras, and immediates. Very tanky. (I hated how squishy he was, how easy it was to cheese the mount, and how ineffective I felt when those immediates are gone.) I hated the way the aura itself was so... eh and had no feat support vs. sanctions.
I love the knight's aura and the powers that supplement it.
I liked the way my warden defended and the feat support his marks have, but in the end it's not the marks or the auras that determine whether or not I like how a class defends, since although they're a cornerstone they're only a piece of the puzzle; it's the way powers interact with them. I love 'em both.
I'm both chaotic and orderly. I value my own principles, and am willing to go to extreme lengths to enforce them, often trampling on the very same principles in the process. At best, I'm heroic and principled; at worst, I'm hypocritical and disorderly.
auras are easier to deal with, from a character AND player perspective, but they can easily become a headache for the DM.
The knight, for example, becomes a completely inescapable defender when they take the flail feats to knock enemies prone on MBAs. Combined with power swap feats and the human PP for multiple "come and get it" uses in an encounter, and you've got a literal black hole.
Either the knight then locks down a gigantic number of enemies (anything in a 7x7 square that he can hit with a weapon vs. will attack) or the DM makes his character useless by sliding him out of position.
basically, a defender who can ALWAYS prevent ANYTHING from geting away from him (like some knight builds) feel like there is no middle ground for encounter balancing....either the DM effortlessly screws over the defender with scads of forced movement (which, btw, still has to hit), or the knight says "no one gets to attack anything but me"
I still think that's not necessarily the fault of the aura, but the feat support that goes with it. Warden builds can, conceivably, be almost as bad. In the end it's the way the entire character is built.
That said, I think a better way to phrase the original question is "Do you prefer defender classes with aura mechanics or defender classes with marking mechanics", in which case I'd lean toward the latter, because the classes in question tend to have a lot more leniency with what you can do.
I'm both chaotic and orderly. I value my own principles, and am willing to go to extreme lengths to enforce them, often trampling on the very same principles in the process. At best, I'm heroic and principled; at worst, I'm hypocritical and disorderly.
Depending on the DM, I prefer Auras since the DM may forget the aura is there and you might actually get to use your Defender stuff for once. With a mark, most people tend to put something on the bad guy who is marked and the DM knows that creature is marked.
