This is one of the few absolute truths. No matter how well trained you are, you are fighting to minimize damage, NOT prevent it. Oh yeah, assuming the assailant is even 25% your equal, you ARE gonna get cut… Just 75% less than he is. To me, getting cut AT ALL should be avoided at any cost. My training is in Aikido and Krav Maga. Though I feel rather novice in the latter, I am very impressed with its potential. Still, the risk of being cut can NEVER be eliminated.
My rule of thumb has always been that if an assailant attacks with the knife pointed at me, in line with the forearm, kick his ass and take it away from him. If, on the other hand, the assailant comes at me with the edge pointing backward from the palm, edge out, shoot him fast or run like hell. This man knows what he’s doing and assuming he has the “drop on you” IS gonna hurt you.
The only advantage of being assailed with a knife, assuming it’s frontal, is that it is almost never immidiately fatal. As Blake aptly points out, a knife is just as capable of causing lethal wounds as a bullet; the bleedout being many times that of a pistol round. However, even with minimal defense, the chance of interupting CNS function is, at best, remote. In nearly all cases, committed persistence with a handgun is critical to survival. Ergo, don’t respond to an edged weapon attack with an edged weapon.
This said, I underscore the admonition to train in as many martail disciplines as possible. In terms of fighting with a gun, I think too many ignore extreme close quarters training. 98% of shootings happen within less that 5yds. In that distance, all that practice at accute target aquisition is worthless. Furthermore, I personally feel that organizations like IDPA, and most civilain training programs are remiss in emphasizing belly-gun techniques. These are more likely to save one’s life than fine target aquisition and a smooth-as-butter trigger squeeze.

You make yet another GREAT point, Rob!

Stay Safe.