Have used transfermate in the past and found them good, quick and cheap. The only hassle with all of these businesses is if you don't have an account with them already. In order to set up an account they need various documents in order to verify your identity, similar to what is required to set up a bank account. They do expedite the process as quickly as possible but you'd need to factor that in if it is an urgent transfer requirement (but perhaps if you don't use it this time it is worth investigating for next time!)
The other thing to note is that certainly transfermate used to have a minimum amount of €1000 but I can't see that on their T&Cs any more.