I just made a test booking with them for my holiday in August and they were £63.00 more expensive than booking direct with Eurotunnel. £420.00 vs £357.00
Had a look at their website, but could find no mention of being ABTA members or anything else to say your money is safe with them, which would put me off.
If I have missed something and your money is safe then they might be worth a quote.