Underwhelmed with the 60D - is it me, or did I get a dud?

I've had a Nikon D90 for the past 5 years. I'm not easy on my cameras, and for the past year, noticed the performance of my D90 going downhill. Nothing specifically wrong with it, but softer focus, worse low light performance, and weaker colors. A friend of mine let me play with her 60D and it looked good so I figured I'd give it a shot, got it with the 18-200 lens. I primarily use it to take photos of my kids.

The 60D does do a nice job with colors, and gets a nice, sharp focus....when I can catch it. But while I've got some nice shots, I just can't seem to love this camera. A few of my issues with it:

- I hate the focusing method. The autofocus does  not work well for me at all, so I switched to the single point focus. This works better, but still struggles to capture the focus I'm trying to get in the moment. And I haven't figured out a way to easily adjust the points that you focus on, which was super easy with my Nikon. You have to go into the menu to change it, way too slow for me.

- This camera is a lot slower than I expected. It doesn't keep up with my kids well. It's OK but I expected more. It's also much slower reading and writing to the memory card. I get a lot of shots where the image doesn't come up for preview because it's "thinking" and the red light is on a lot for me.

- If you don't keep the lens locked, it immediately opens/zooms out by itself. I hate this. Will be walking around and all of a sudden I'm walking with the camera fully zoomed out - it's already big enough and in danger of getting knocked around even with the lens not zoomed out. But when I lock it I end up having to slow down and remember to unlock it.

I really wanted to love this camera. Is this typical of all 60Ds or did I get a dud? Am thinking of returning it and trying a new D90 to see if that gets me back to what I want.