How do you choose among them? It's simple. First decide whether you're looking for a workgroup product or an enterprise product. Then decide whether you want to consider mainstream products, up-and-comers or both. (I would place a value on which you find more appealing, and include the weight of that value in your final decision. Some like big players for their stability, others like smaller players because they feel they move faster.) Then do an extensive, weight-based comparison of the features of all products that are on your list. (A weight-based, comparison assigns a weight, or importance, to each feature, and gives a higher score to a product that has a feature with greater importance to you.) Find the top two products that meet most of your needs, as none of them will meet all of your needs. Then do a price war between the two. (Notice I am doing price last.)
My personal experience shows that most end users do not have the time, energy, or expertise to do what I just described. The biggest issue is that the space is moving so fast, it's hard to even know what questions and features to ask for. The second issue is that what I described above takes a lot of time if you haven't done it already. Therefore, I believe that the best way to do that is to hire an independent consultant to do it for you. Just make sure that they're not being compensated by any of the vendors you're considering. The two national companies that do that type of service right now are The Storage Group and Glasshouse Technologies.
Read Pierre Dorion's answer to this question.
This was first published in June 2004