The alternative interface that I'm served when using my tablet is generally excellent - very easy to use - but the search function is missing from the forums.
Hmm. There definitely is a search box in the forums when I'm browsing on my laptop and very useful it is too. And it's functionality that's no less useful when I'm on a mobile device, in fact, given that the viewport is smaller and browsing is often slower and more laborious (scrolling, page loading), the use case for providing it on mobile may even be stronger.