Now, I'll be honest with you - I've never heard of them before you mentioned them. Like a say, stick with the big name brands, there are so many dodgy sites out there it's the safest. Many review sites will just republish reviews and info that they got from the Bingo sites - as they earn money for referring people. We do the same, but we still try to be impartial.
I notice from your anchor text though, you're interested in link building. Can I suggest you drop in to Text-Link-Ads and have a look, there's a few nice Bingo links with nice PR you can get through there - they'll do you more benefit that in the forum.
If you're pointing Google at two different versions of the same site co.uk and .com, you could trip the duplicate content filters and knock 'em down the rankings.