Writers conferences – are they worth it?

I've just signed up for the weekend writing fest that is the Festival Of Writing at York University in a few month's time.
I have been to one other event like this, at Winchester a few years ago and although there is much to be said for these intense gatherings of scriveners and industry experts, publishers, agents and book doctors, I am still nagged with some doubt about their value.
It probably depends what stage you are at as a writer.
I do remember the permanent scrums that formed around anyone of any perceived importance (agents/publishers) who moved around in the centre of a revolving crowd of hopefuls brandishing manuscripts. Not sure that's my idea of fun.
From my point of view, it's all about contacts and feedback and I will be getting two one-to-one sessions for my admission fee, one with a Random House editor and the other with an agent.
Despite significant reviews of my books, rejections are still the norm. Having said that, rejection is part and parcel of being a writer seeking publication. There is a long and notable list of writers that have been turned down by luminaries from the big six majors and, whereas it might be easier to get a deal with an independent house that is happy to read your work it is still hard to decide whether self-publishing is the route given the technology and the trends in the publishing business today.
But, even if you self-publish this doesn't mean you will sell wagon loads of books, any more than you would with an independent publisher.
And I hear that unless you sell a jumbo jet load of books a mainstream publisher will not be interested in your self-published work.
So, we will see what we will see but if anyone has any experiences or advice regarding how to maximise the investment in a writers conference then please let me know.