For me, using these new methods puts me on the spot. If I'm going to send someone a picture, I'd rather not feel like I'm under the gun with holding my thumb down and releasing/sending a message (or whatever gesture it is).
Also, the Microphone is very confusing. For my non-techy friends, they all said they thought it was dictation. And they said if there were going to talk, they would have called the person. Don't get me wrong, I'm sure Audio-Messages are handy in certain scenarios, but I don't think it should have a dedicated icon on the Messages screen.
I use the audio messages only when I know the person I'm calling isn't going to answer, and I'm just going to end up leaving a VM anyway. Many of my friends are teachers, so if I need to leave them a message during the day, that's faster than waiting for their phone to dial, ring four times, and kick to voicemail.