I got a Malekko E.Filter a little while back and that was great, except for one problem: the filter is a little hard to crack open, especially with single coils. I could make it behave using a boost but given that its size is one of its key virtues, that seemed a little bit silly. That said, the quackyness of the E.Filter is great, and I really enjoy playing around with the filter opening: low E-string work that nearly opens the filter but doesn't, making all sorts of great sounds. So I grabbed a 3 Leaf Proton from Prymaxe. With the gain pot, there is no problems finding a sensitivity that suits. One difference is that the Proton is a bit more wah-like and less quacky than the E.Filter. Also, the filter takes a wee bit longer to close than would be ideal. Nonetheless it is a great unit and I'm going to have a lot of fun with it. Regarding Prymaxe: delivered to Australia in 5 working days. Amazing; some of the shops in Australia can't match that (with the exception of Pedal Empire!). Very happy with that result.