Hiya, I did register on it when it first started,
I spent absolutely ages going through the list of business categories to show what our company does, and put in as many details as I could.

In the last 2 years I have never gotten one contact with any interest, but I do get the daily email of contracts, usually there is about 1 or 2 software development contracts on there per day, so I have spent time going for them in the past.
I wrote up a long spec and quote for the work, but I think because my company doesn't have Liability Insurance, or other things like ISO recognition, or a properly defined equal opportunity document, or sexism, and disability procedure (we have 2 directors and use a network of freelancers so have our own online office standards that dont really conform to normal office working procedures), then I have never even had a reply from anybody I have sent a spec off to.

Now my company has done the Uttlesford council website, the St Edmundsbury council website, the audio visual systems in the Houses of Parliament, and the government question time software for the Welsh National Assembly, so I was a bit miffed that we dont even warrant a reply to say why we werent considered.

I would say try it out, but be careful on spending too much time on there because my experience is it isnt the best way to get government work.
In my experience, they have to advertise contracts by law to the whole of Europe for all SME's to get a chance, but in reality, most of the jobs have a contractor in mind allready before it even goes onto that job board.

Cheers,

L