PTR's new "Vent" line of suppressors are a really cool use of new technology to better execute an old design concept. The idea is that forcing muzzle gasses through a porous material will work well to slow and cool them, providing good sound suppression. Back in the 1940s (through the 60s or 70s), this was done with wire mesh rolled into a tube. Today, PTR is following the same principle to a much finer degree by using additive manufacturing to produce titanium with "purposely induced porosity". Essentially, titanium foam. Their design is furthermore done to minimize back pressure, allowing guns to run suppressed without modification and for shooters to not get a lot of noxious exhaust in the face. And on top of all that, the suppressors are quite light. What's not to like?

Well, the price, for one thing. In addition, these cans require periodic cleaning, unlike most centerfire suppressors. PTR suggests soaking them (or better, using an ultrasonic cleaner) every 1000 rounds for pistol cartridges and every 1500 rounds for rifle cartridges. This is necessary to prevent the porous titanium from clogging up with carbon.

Is that a worthwhile tradeoff? Well, that depends on each person's specific desires and needs.

Pew Science report on the 9mm Vent 2:
https://pewscience.com/sound-signature-reviews-free/sss-6-131-ptr-vent-2-sp5

Pew Science report on the 5.56mm Vent 3:
https://pewscience.com/sound-signature-reviews-free/sss-6-135-ptr-vent-3-mk18-556