Let's check the features...
High quality streams: not interested. I'm happy with what's up already.
Video podcasts and full-content RSS feeds: Don't watch or listen to podcasts, and I don't use RSS.
Exclusive member content: Tempting...
A custom title of your choice: I don't use the forums often enough to justify this.
Early access to upcoming site features: I doubt I even use a quarter of the site features available now. Have to say no to this as well.
Ad-free viewing of the website: I use Adblock Plus and NoScript, and I've never once seen an ad with both of those enabled.
Automatic contest entries: Doesn't matter to me, because the vast majority of contests I've seen are only applicable to those in the US.
Exclusive member forum access: Once again, I don't use the forums often enough to justify this.
Audience panel membership: This is probably the only thing (apart from member content) I'm interested in.
Final tally, only two features actually interest me. Spending £13 on two features isn't exactly cost effective, so it will have to be a resounding no from me.