I always found them really helpful, fast to reply and so on until the most recent submission that I made. I'd just finished my third book at the time and I sent it off to them. It all went well, they asked for the full manuscript which was the first time that had happened to me, so I was all excited. They told me to wait a few months for a response, six months later I got back in touch and they told me that my submission had 'gone missing' because a literary agent had moved on. They claimed they were re-reading it but with them getting back to me within a week with a standard rejection I knew that they hadn't.
I realise I must have slipped through the cracks but it made me think twice about sending anything off to them again. They didn't handle the situation very well in my opinion.