Decorative kesubos are kosher. However, it is more likely to have a mistake on a decorative kesubah than the standard ones. Decorative ones are often hand-written, and a mistake might not be caught. The standard ones were checked multiple times, and the same one is printed off each time.
I was told that I should use a standard printed one for the wedding, and if I wanted a fancy one, I could get one to hang up – but it wouldn’t be my “official” kesubah.