From what I've had.

Tials are great once you figure out what spring is proper for your application. Awesome sound, function.

HKS SSQVs are decent as well, or at least they were back in the day. Great if you like the sound of scared peacocks.

TurboXS RFL was really loud, worked alright but had to be hidden away. Not much for being a compact package.

Basically, they'll all leak eventually as the rubber deteriorates. Every last one of them has either a diaphragm or an o-ring to seal it somewhere in the design. O-rings are a lot easier to source.