PingChat! had problems a couple weeks ago with lots of delays but that's pretty much gone now. I haven't used Kik and don't want to give it a try because my primary use for PingChat! is group chats. Even though they don't say what the max group can be I figured it to be 15 including yourself. Anything more just gets sent like a mass text message and replies are individual to only the sender. If a messenger doesn't have that then I would rather text for individual people.
Ping chat is great. You can send pics, music, location and contacts. I can also put up a avatar. I dont get how anyone likes kik better. Its all over twitter