I did use them twice with smaller amounts and had no problem. But you have to have a service you can rely on with larger amounts.
I think it probably wasn't a scam in my case, but when you have £5k of your money just disappear, there is no information at all from them and, even worse, they are obviously not even reading your support tickets then you do start to worry. It may be I was just unlucky and got caught out by their change of banking, but that shouldn't really need to affect their customers.
It all says something bad about the way the company is run and I certainly would not use them again.