I've never used DTS but I have a love-hate affair with SSIS - I think it's incredibly useful and almost always appear evangelical on the topic, but as stated by an earlier poster it is capricious. About two thirds of my time is spent dealing with what are quirks/limitations of the system, for instance I often pull my hair out trying to get the data types of unicode and non-unicode to match up between datasets and tasks, as opposed to actually developing the actual flow.