I have one, I bought it, and I think it's worth every penny- as long as you're an active member. For me who's on for most of my waking hours it's a wonderful thing. Subs are also good for people who are big in the community, especially with polling because if you have hundreds of watchers polling is a great way to quickly get feedback. And this is an excellent example. : )
I know lots of people who deserve them, and can make use of them, who don't have the money so I've bought about seven people subscriptions... it'd be more, but I'm not an endless font of money... as useful as that'd be.