I've used the Dromlites for many years, and they've never leaked. I've used them inside my pack to transport water to a dry camp. About 10 years ago, I used one with the "hydration kit" attachment for a summer, and never had any problem (I gave it up because I just don't like hose systems.) I used a Dromlite with a retrofit kit, not the "Hydromedary" version they also sell - but the Hydromedary looks to be about the same, and have a screw-on top that will mate to the Miniworks directly.

As with any bladder, when you first get it, you want to fill it at home and let it sit in an empty bucket overnight, just to be sure there are no leaks.

By the way, based on my own personal, decidedly unscientific, experience the Miniworks may not be the lightest, but it's the most functional and reliable. There are some things that are worth a bit of extra weight. (Don't tell the rest of the folks on the forums I said that. )