I must admit, using Idera DM makes life a lot easier for any DBA. Some DBA might call you lazy for using a tool like this, but I seriously disagree. DM can give you a deep insight into any SQL server, almost instantly. My former CITO's opinion after about 3 months of using DM was, how did we ever get along without it.
I've been using DM for almost 12 months now (since 3.5). I recommend it to all my clients (I think I should start charging Idera some commission).
It is true that in same cases it might cause overhead on your server, but finding a solution to a problem, that otherwise might have been eluding you, is always worth that cost.