I've considered using you on my level 62 hunter. The thing is, I don't really enjoy playing him that much, and I can't imagine suddenly adding a boatload of spells and abilities is going to make that an experience I'd like more. In fact, if he did good DPS I'd probably get angry, since I know I'm not a particularly skilled hunter, and if he did poor DPS (which I'd expect given my low skill on the character and lack of experience with the last 30 levels he'd have just leapfrogged past) I'd get bored even faster. It's not terribly compelling.
I've actually considered getting you just to boost one of my pallies to 90, but not because I want to play him - we could use another paladin for Devo Aura on heroic Thok, frankly. It's a much better cooldown than Demo Banner, and I could also BoP or HoP or whatever it's called now to a healer so he or she could keep on healing through the silences. But that's less about my wanting to play a paladin and more about the game having an incredibly annoying fight designed so that one class just breaks the encounter, and if anything it makes us all feel dirty.
It's a case of a feature not being designed for me. I accept that. But it does kind of leave me with a problem - I'm getting it one way or another. Do I do anything with it?
Now, if I'd taken some time off from WoW and was catching up with friends, this would be ideal. But I didn't - been playing all through Mists of Pandaria, and other than the design for daily quests that first came in with 5.0 I've loved this expansion. Nothing but praise for its story, for the patch 5.1 and 5.3 experiences, and patch 5.4 provided a heck of a raid (admittedly, I don't know if any raid is good enough to hold my interest for a year, but that's another issue) so I've been here all along. And it seems like my particular brand of madness means I'll never need to buy the level boost service, and I might never even use the thing.
Then again, I often find level 89 painful. You're so close, but just not quite there - I can imagine snapping and burning the level boost at that point just to clear that last level, and to avoid having to level my skills. It's not like it's a huge skill imbalance to do that, but it's also kind of insane. It's an afternoon's work at that point. So I'll probably try to convince myself not to do that,but I know me. Even awesome zones like the Dread Wastes get old the fifth or sixth time you see them.
In the end, Character Boost, you are a feature I'm glad was added to the game -- you'll make it much easier for returning players to get back in the swing of things, and people with legions of varied alts might make great use of you, but for me, the guy who levels warriors (and one shaman) it seems like I'll never come up with a use for you.
Unless I use you on my horde shaman. Oooh. There's an idea.