I just did that with my 10g.
My fish definately like the live plants better. They can eat food and algae off of them and they make better hiding places for them. I also think the fish stayed away from the fake plants because they were stiff and might have injured them.
I got a few java ferns and anubias and all of them seem to be doing fine. I had to change my lighting, set up a timer for the light, and add more gravel to anchor the plants in, but I'm happier now with the live plants.
There isn't too much more to worry about except caring for the plants by trimming bad leaves, maybe adding a leaf fertilizer, and making sure the lighting is sufficient.
Go for it. I'm sure your fish will thank you for the change.
-josh