Well, the company I work for uses templates. We do this because of the number of items that we list per week. The only downside that I see from using templates is that everything looks the same. You can change the template, but you don't want to do it too often.
I think it is good to use a template if you are listing alot of stuff. But if you are only putting up a couple of listings per day then it would probably be better to custom create each one.