No, it's got a pretty on-the-rails feel to it. You might want to try different strats against the bad guys but that's about it. Try out different endings (there are two, a paragon and a renegade ending).
But, after finishing it I'm kinda wondering why I bothered. But the reviews are mixed. Some love it, some are meh, others hate it cause OMG FEMALE TURIAN WITH BOOBS (even tho we don't know if they're actually boobs or not because she never takes her armor off. It could just be her carapace is elongated to give the impression).
The only thing you'd probably do is wait for it to be 50% off to pick off the achievements. But it's not entirely worth it even for that unless you're a strict completionist.
If you're really interested in Aria and why Cerberus took Omega, then you can read the comics. The DLC is just the finale which you can already guess what happens so it's nothing shock and awe.
In other news I forgot the information about Lego LotR having voices. But, I also understand why (differentiate between Elvish and Common). Still weird. Used to having a version of Simlish.
Thanks for the info; I think I'll wait. I've been having a hard enough time replaying ME3, not because of the endings, but because I'm so sick of finishing a mission, only to see loading screen, cut scene, loading screen, cutscene, loading screen, dream sequence, loading screen, report to Hackett, loading screen, play again. I don't care about the endings anymore, just give us skippable cutscenes!
Dishonored and Lego LOTR are both possible additions to my XMas list.