I would not go as far as mdwu when criticising ARCSERVE 2000 but I would say it is very buggy and unforgiving. The support for the product, knowledgebase, updates e.t.c is not always easy to find and unless you have a paid support contract you are totally on your own. The forum here is much more active than CA's own support forum. For one software product you really need to rely on and feel comfortable with it does not inspire confidence.
Just my opinion.