The founder of Bright Network is also the founder of 'Oxbridge Applications and I'm sure most of us were told to stay away from them... It's a good event with regards to gaining an insight into your chosen career, meeting like-minded students and getting your face known. I don't think it goes beyond that as a general rule.
The only recruitment agencies who make things happen for you are SEO/Rare, but obviously not all of us are dealt with that card.