<snip>"it works exactly like a familiar"</snip>
I have to say that this one is crap. You lose the benefit of a feat for an entire year and a day, AND lose a boatload of XP?
I never use familiars because of that, and I certainly wouldn't waste a feat on something that's more a liability than anything else.
No wonder familiars have a tendency to 'disappear' and be ignored. Nobody wants to get screwed.
Well, you can get a familiar for a feat, too (Obtain Familiar), and it works exactly like a normal familiar. So, yeah. I've also seen DMs who didn't enforce all the penalties if your familiar dies, and most DMs don't usually just viciously go after familiars IMX. If they did, then yeah, I'd be hesitant to use one, also. Do note that familiars can be Raised, and don't lose anything from it, too. So the 1 year thing is only for low level guys who can't afford a Raise Dead.
Also, if you've multiclassed into a PrC (and who hasn't...), the XP loss isn't that horrific, since it's based on your wiz/sorc levels. You make the save, and lose a few hundred XP, which is not much worse than if you'd cast Limited Wish or something. You get all the best familiar benefits by 5th level, anyway, and even if you drop out at 3rd (for Master Specialist or something), you don't miss much.
Although, this means that you're actually better off with your normal familiar as a multiclassed caster than you are getting one from Obtain Familiar.