I've got an electronic flow controller, but I don't use it. I prefer just using the pressure switch. I use 6mm microbore hose and I get a perfect flow - nice and fast - without the hassle of a flow controller.
Try it, seriously, before you buy one. You just work quickly; it's class.
same here 
I should've listened to you in the first place and saved meself some dosh and messing about.
to be fair I have to thank peter fogwill for that
I could have saved some money and time as well if I listened to him earlier, I just thought no it can't be that simple and tried all the advice on here, only to find it is that simple