The Elder Wand not working for Voldemort? Say what?

[Carol]

No: HPFGUIDX 181733

Carol earlier:
> >
> > What I want to know is how Voldemort "knew" that the Elder Wand
wasn't working for him ...
> > 
> > Huh? None of it makes any sense. If, indeed, he accomplished
extraordinary things with the Elder Wand, which seems to work for him
just as well as his own wand ever did ..., what is Voldemort's
problem? What flaw does he see in the Elder Wand? 
> 
> bboyminn:
> 
> Well, you said it yourself, the new (Elder) wand worked as good
> as his old wand. If fact it worked as well as any reasonably
> compatible wand would have, and that is the point. It was a
> normal conduit for Voldemort's extraordinary magic. But that
> is not how the Elder Wand was billed. It was suppose to be
> an immensely and extraordinarily powerful wand, and that is
> what Voldemort did NOT see - the power of the Elder Wand head
> and shoulders above any other wands. 
> 
> So, it is not a question of working or not working for him. 
> It is like buying a Lamborghini or a Ferrari (fast expensive
> cars) and having it drive like a Ford Pinto (cheap low powered
> econo-box car). Yes, you can drive it, it acts like a normal 
> car, but it would certainly not be living up to it's reputation. 
> Voldemort was expecting a super-fast high-performance racing
> car, and instead he got a Soccer Mom mini-van. Still in the
> right hands a Soccer Mom mini-van can be capable of 
> extraordinary things, but it simply never equals a super fast
> race car. 
> 
> Wands and racing cars; it's all the same.
> 
> Steve/bboyminn
>
Carol:
Except that there's no indication that the Elder Wand works like a
Soccer Mom mini-van for Voldemort. it created nagini's bubble, didn't
it? and it works as well as the old wand that chose him in the first
place, the one that created the Horcruxes. Exactly what extraordinary
magic does he attempt to do and fial? None that we see. In fact, he
doesn't even start thinking about the wand not worbeing as
extraordinary as he expected it to be until right before he sends
Lucius to summon Snape. I don't see any evidence that the wand failed
him or let him down in any way. Sorry; the mini-van vs. ferrari
explanation doesn't work for me. Now if he'd struggle with it as Harry
did with the Snaptcher's wand, I can sould see why he'd know that he
wasn't its master. As it is, I'm not buying.

His old wand was no "mini-van," either. it was a powerful wand,
perfectly suited to him, with which he had, according to Ollivander,
performed "great but terrible" magic. and this wand does the same
thing. How can he tell that his "extraordinary magic" (of which we see
no evidence except Nagini's bubble) results from his own power rather
than the wand?

It's like a skier who wins an Olympic gold medal but complains that
his skis weren't good enough and it was only his own extraordinary
ability that won the medal. (How could he judge equipment that won him
the gold as unsatisfactory?) And with a wand, it would be even harder.
If it does the job, performs the spell, kills the victim or whatever,
how do you tell excellent from extraordinary? (And his old wand was
excellent, perfectly suited for him; it's not as if he'd been using
Lucius Malfoy's "poor stick," which can perform Unforgiveables but not
whatever it is that distinguishes Voldemort from other Wizards?
(Flying without a broom? Snape can do that!)

Show me the evidence that the wand wasn't performing for him and maybe
I'll change my mind. As it is, his complaint just seems thrown in and
groundless, a mere excuse to murder Snape (who's done nothing wrong
that Voldemort knows about--if he did know, of course, he wouldn't
need the Elder Wand excuse!).

Carol, not convinced by analogies and needing canon support to
convince her that the wand's performance was recognizably inferior to
what he expected from it