Of course it is a good idea to set up the spam filters. Believe me you will get many once the search engines find you.
Delete straight out negative comments - oh yeah.
I suggest to be open to the comments that may not be glowing but offer constructive advice. It may be hard on the ego but something could be learned as a result.
Though, I hate it when the writer/blogger argues back. Feels like a waste of my time as a reader.