I'll be honest, I never saw the point of training with sharps- it adds a level of danger and excitement but there's no real way you can practice- even without the intent to do harm, the chances are a good deal higher that an injury can be sustained. Just my $0.02.
There are some legitimate reasons for it.
The bind - sharp swords BITE. Steel blunts don't. Things like the windings are infinitely more interesting with a sharp sword. With a blunt, oops, I got stabbed. With a sharp sword, there is that split second transition from "hey look a bind" in which you evacuate your bowels because you can actually feel the oppononts sword release from the bind and start moving towards you.
Blade presence - weight and length on blunts are pretty close to historical style, but there is a difference in blade presence with two sharp swords. I can't put it into technical terms, but there is a completely different level of fear and respect when dealing with a sharp sword. Safety gear and blunts are a big artifact in fencing where we aren't nearly as worried to have "double kills" or to get hit repeatedly. Granted that's the nature of training, but without the "real life" fight with a true sharp sword looming anywhere in the future, we train under a different mentality than our predecessors did.
But I would NEVER advocate anyone ever doing it without the guidance - and probably participation - of a very knowledgeable, experienced, and safe instructor.
