New tyre here and I couldn't be happier with it.
I got a great deal on a Specialized Chunder 2.30 a few days ago and didn't think twice about buying it. I had already rode a few times with these tyres (on my dad's Bighit) and loved their performance. This is an excelent rear tyre, the spaced knobs provide real grip on tough turns, with the right pressure on, you don't feel the bike sliding around like crazy.
Also, the 2.30 size is perfect for DH, they're not heavy at all and a larger tyre size would be unnecessary.
Here's a pic testing it: