At least in the more vocal parts of the community, I'm definitely in the minority for not liking experience boosts. Whenever another double XP weekend rolls around, I sigh, shake my head and go off to sulk in a corner / focus on playing my max-level characters. It's not great - I'd much rather be part of the shared experience of having fun together, but I just don't enjoy having my experience gains increased to ludicrous levels whether I like it or not. I don't mind XP boosts as items in the game which you can take or leave, but enforced "bonuses" annoy me.
You don't even have to dislike them on principle to see why they can be annoying - I think it was on OotiniCast where I heard someone express disappointment the other day that his levelling experience with his friend had become completely screwed up since one of them had pre-ordered the expansion (and had therefore had the XP boost applied) while the other one hadn't. I do hope that Bioware implements an on/off toggle for these things eventually.
I often feel that levelling in this game, and the "side quests" in particular, get a bad rap that isn't really deserved. They absolutely are worth doing more than once, and as far as unnecessary repetition goes, nobody says that you have to do all of them on every character and in exactly the same order.
Sometimes I wonder whether "levelling is boring" isn't a self-fulfilling prophecy. If you think that levelling is boring, you're probably going to try and get it over with as quickly as possible, therefore focusing on repetitive and "efficient" activities to level - which are boring. Meanwhile those of us who are willing to take it more slowly get the chance to engage with all kinds of different content on our way to the level cap and end up having a good time while doing so. But anyway...
Part of why I dislike double XP weekends in particular (aside from the inability to opt out of them) is that they seem to encourage people to "play stupidly", e.g. spam Kuat Drive Yards for maximum XP per hour while complaining all the while about how boring it is.
And this is why this whole 12x XP thing actually has me somewhat intrigued... because it works so differently and seems to want to encourage deeper engagement with the content. Even if I feel that the generic planetary quests get a bad rap, I won't
disagree that the class stories are the more interesting part of
levelling a new class, and this event actually pushes players into paying attention to them, even if they don't want to do anything else. (Not that this will prevent people from using the event to try and power-level through class stories by space-barring through everything, but at least it's very clear that this isn't the point of the exercise.)
I have a couple of characters that have been stuck in the mid-levels literally for years since I accidentally made them a bit redundant. Specifically I created a Sorcerer and a Powertech relatively soon after starting to play the game, and then ended up re-rolling both of those classes with my pet tank and levelling them to cap with him instead. Part of me thinks that I should have just deleted those older characters by now (why do I need two Sorcs and two Powertechs when they are not even my favourite classes), but I'm just too sentimental. They were some of my earliest creations!
So I've decided to do the unthinkable and use the "class levelling event" to maybe get these characters to the end of their personal stories at least, to give them and myself some closure, even if I don't really know what else I'm going to do with them afterwards. Wish me luck...