I think it's quite good now that I've used it a couple of times. They definitely had a few teething problems, when I first tried it it kept telling me my session had expired when i tried to do a search but I guess I was using it just after they deployed it. It is often the case that it takes a few weeks for them to iron out any annoyances but it seems like a step in the right direction.
Been trying to get tickets to swindon from it and it kepps saying page unavailable every time I get near purchasing. It also seems to delibaretly display the most expensive fares.