you are comparing a dynamic with a condensor. there will be a huge differance in sound and applications. In my opinion, condensors will almost always be better than dynamics on accoustics. I have never used the AT 4040 so i dont know about it, but I have an AT3035 that I like to use when recording screaming or yelling vocals. I use a Studio Projects B1 or C1 for most other vocals. I think that if you are looking for something for both accoustic and vocals, I would recommend a condensor.