Major difference in air flow. I use the PT with a Kensington. This is the only way I vape. Will work great even if atty hole is blocked. But even more important is more hits before I have to top off. Only getting 25-30 with sealed. Have gotten up to 75 with unsealed. Also completely dries out cart filler with unsealed, still wet with sealed. And most important, better hits and vapor production.