We use Idera DM at work. It really does do the job and does it pretty well. There are a few counters that I'd like to change out if I could, but overall, I'm happy with it.

That said, I've made the attempt to either replace Idera or add to it with Confio Ignite. While it doesn't cover some of the more traditional monitoring quite as well as Idera, it's a step above on the wait state monitoring & T-SQL performance metrics.

Sometimes, it comes down to the style of the tool as much as what it does.