Great for the cats but very "drafty"
I have just ordered my second SureFlap having had the first one for over five years. The cat-flap is great for my three cats, making them feel secure in their own home as stays are left stranded outside and there is never an issue with them being stranded (as they were on occasion when I had a magnetic cat-flap) providing you change the batteries when the red low battery indicator flashes on.
On the down-side this is probably the least draft-proof cat-flap that I have ever had allowing cold air into the house at the top of the flap-door as well as the poor brush finish around the edge. Everyone who has been to my house comments on the draft (I live in a house that is less than 6 years old and rather well insulated)
I would have like to have tried the new Catmate flap but it unfortunately requires more space.