Your simple question is hard to answer and you actually asked for opinions. So....
Babies and kids don't hold still, not until they are about 25. (Mine are about 40, but I have grandkids that don't hold still.) Capturing the best moments for me, comes from a camera in my pocket or that I can grab quickly. The current version of that camera is the Sony HX20V. It does both good pictures and good video. I can get better video with a similar camcorder to yours, but I have to "pre-meditate". In other words, I have to have made the decision to have it in my hand or over my shoulder. An example, would be a sports event of some sort where I know I'll be on the sidelines taking video.
But don't send back the Nikon. When you want stunning enlargements, you need what it offers. If you get 10 stunning enlargements by the time the kid is 25, it will be worth every penny.
And, don't send back the Panasonic. When you want stunning video with good audio, you need what it offers. With the viewfinder, you can stay aimed at your kit and get clips of him/her scoring the tie breaking goal. If you get 10 stunning clips by the time the kid is 25, it will be worth every penny too.
Since you are about to be a Dad, there is another reason to keep both. You need some things to do around the home, because you don't get to "get out" as easily as before. You need some complicated toys that will consume you when your DW needs to get out and you get to stay home.
For photo or video advice, I suggest you keep at least one, if not both cameras where you can grab them quickly. Leave them set to full automatic with charged batteries. All of the technology you just invested in is aimed at people like you that have about a half second to catch the first smile or first step. Keep the gear where you can get at it.
More advice would be to buy the package of Adobe Premier Elements and Photoshop Elements. It comes with "Organizer" that does a marvelous job of keeping track of your amazing kid videos and photos.