I have the Pirellis on my 05', and the Blizzaks on my Disco. Both are great tires, the Blizzaks have some nice, almost mud terrain, tread, and they both do great in the snow. I'd venture to say the Blizzaks are better winter tyres though.
I'm running Blizzaks on my L322. It's what came on it when I bought it about 10k miles ago. They seem pretty good in the dirt, I haven't tested them in the snow, but they are technically a snow tire so it should be better than anything I've ever had before.
As far as the tread goes, they appear to be the ONLY agressive tread-option for 19" rims without going with expensive Duratracs or custom ordering Cooper Zeons. I'm not sure if I'll go with any of those 3 tires on my next set (Blizzaks, Duratracs, Coopers) or throw the whole stupid 19" setup away and get 18"s with a proper off-road tire.
Only time will tell. Rims aren't cheap, but neither are the 19" tires..
Not saying you should- I've had the Blizzaks on for the entire summer and drove 3-4k miles and they're completely fine, didn't wear at all that's noticeably. Not too worried about them since 2/4 are starting to dry rot.