Hi Prairedog... like KSH says it is personal preference, and you must decide what is best for you... though you will get more power and stability if you can be comfortable with cleats on your shoes.

Like you, I was rather nervous, but I wouldn't dream of going without being clipped in to my pedals now.

The only exception is when i am on my mountain bike (not a very common thing anyways) or when I am riding with my youngest son - I just flip the pedals over and wear running shoes otherwise I worry that I won't be able to get my feet on the ground quickly enough when he decides to wobble or stop suddenly