I have one but i never use it for the purpose of a higher cake - i find cake cooks better when they are thinner but thats my opinion, i would rather make 3 layers than 2 if it means a higher cake.
Baking in 4" deep pans is much more difficult. You are far better off baking two 2" deep cakes instead. As Samb88 said the thinner cakes will be much more moist and light.
