I carry a Glock 30 also, and I have three holsters for it. They're all paddle holsters, since I have to disarm to go inside a couple of places on a daily basis.
My favorite is from iTAC. It's a kydex holster that's adjustable to virtually any angle. The gun locks into the holster and is released by a button along the side, right where my trigger finger goes when drawing.
I also have a Blackhawk Serpa. This can be worn as a paddle holster or a belt holster, though Blackhawk now has a line of Serpas that only come with a paddle. It also has adjustable cant, but fewer angles, and it has the same kind of button release as the iTAC. The fit for this holster was a bit snug for my liking.
Both of these holsters were actually made for the Glock 21, but will accept a Glock 30. This makes for a longer holster that is a little harder to conceal, but the excess can be cut off.
And I have a Desantis Viper. It's a leather holster, with adjustable cant and a thumb break, that is built for the Glock 30. I like that it is the correct (shorter) length and that it rides a little high both things make it easier to conceal.
My personal reason for preferring the iTAC is that, once the button is pressed, it releases more easily, which makes it quieter. I want the option of being able to remove the gun quietly in case something is developing but I haven't been spotted by the BGs yet. Such as someone robbing a store where I am shopping. I'd like to be able to draw without attracting attention so I can protect myself if I'm overheard using my cell phone. Your priorities may vary.
"An armed society is a polite society." Robert A. Heinlein
"After a shooting spree, they always want to take the guns away from the people who didn't do it. I sure as hell wouldn't want to live in a society where the only people allowed guns are the police and the military."
William S. Burroughs