The healing in Acts 3 was dramatic, it caused crowds to gather around Peter and John in the temple but, even with all the drama, the healing itself was not the focus. The man was healed in the name of Jesus and Peter used the opportunity of the crowds gathering  to point to that name again. His sermon wasn't used to tell people that God can heal and he can do it again - even though that is true. The focus of attention is the healer not the healing, the healing is just the context and catalyst for people to hear about Jesus.