AU uses these weapons, against the better judgement of its safety marshalls.
I have seen them break far too often for safe use in NERO. I've got a scar on my right shoulder from a thrust where the core slid through... I bled all over the tunic, sweatshirt, tabbard, and shirt it cut through. Yes, that bad.
Really nice, and very light, but in NERO safety terms, totally illegal. many of them have sharp and rigid crossguards.
My PVC weapons would snap a hadfang in one shot... Greg had his 2 hander for about a day before the core went.
The shortswords are the longest lived, and safest of them so far. Even so, they rarely *actually* have 2 inches of progressive give (of the variety that doesn't fold over onto itself) and don't have the requisite thickness of foam.
That thickness is based on a 1st or 2nd gen heavy core, but even these need it from time to time: I've seen someone get hit in the face, and have even one of these rupture a blood vessel in the eye of the recipient.
Are they safe? are you effing kidding me? most of these examples are caused by people who should never have picked up a sword in the first place. These are safe blades... but only when they come up against other ultralights.
In a game where PVC is still the "according to Hoyle" norm, no, they break too easily, (Greg and Drew prove that one parry is all it takes, and all I did was get hit.) and are small enough to get through the visor of my great helm.
The safety rules would need to be updated to reflect the relatively recent lack of round foam, and most of the heavy weapons would need to go away. That might take a few years.
your mileage may vary,
-Gid