Re: Not good
f someone is going to try to murder me, I would very much prefer that they attempt it with a knife instead of a gun. You have a better chance of surviving;
Only if you've been trained in hand-to-hand combat and thus know how to deal with a knife wielding attacker. Otherwise your odds really aren't any better or worse. If anything you're more likely to bleed out from a knife wound that a gunshot. Guns most often kill from shock, which is slower than bleeding out usually and gives you more time to get help. One slice to a major artery and you've got under two minutes to live unless there's someone right there who knows what to do.
they have to get in close which is a psychological barrier that will stop some people
Someone who's willing to pull the trigger on a human being will have no psychological problem with stabbing them. And getting close is no problem for someone who wants to kill you unless you've got personal security. Knives, even biggish ones, are very easy to hide.
and -even if they win- they will probably be covered in a fair amount of evidence which will increase their chances of being successfully caught.
Fair enough, but that's not going to matter to you at that point.
Consider, also, the scale of the thing. How many victims could a knife-bearer reasonably expect to get away with before being dogpiled/shot? Compare that with the usual victim count of someone with an assault rifle.
One mass stabbing left last year 29 dead and 140 wounded. Link. Another in 2012 left 22 school kids wounded, many in critical condition. Link. Another left 6 dead in a railway station. Link.
In other words, pretty similar to what you could expect from a gunman shooting up a public place.