I use them and find that generally they are good. I deposited with a credit card and was ready to bet straight away.

They claim to suspend betting about 1 minute before the race, but sometimes it can be earlier, and occasionly later....
I haven't withdrawn any money yet so I can't tell you about that.
The bet process could be sped up, but as long as you are prepared to bet at least 1 minute before jump time you should not have too many worries....