You need to consider the situation described in the question. If you need to detect something that would need you to examine one by one each of the queries sent to the server, then Profiler would be the answer, but if you need to determine some kind of "total
aggregate" for some parameter, then it is more likely that a DMV will provide you with that value.
If you have some specific example of question that you find unclear, perhaps you could post it here (or in one of the SQL Server groups) and we can explain why or why not it would be best to monitor that kind of information with one tool or the other. Or,
if you are familiar with both tools, you could actually try it out: use both alternatives on a test instance, and try to determine the result in both ways. You will typically find that out of Profiler and the DMVs, only one of them makes it reasonably easy
to find the results that you are loooking for.