This is something I can really agree about, even if in this context it sounds more like an ad. But I prefer Tableau over some premade dashboard, because Tableau is really incredibly flexible. As far as I know, I haven't seen any dashboard even distantly closing on Tableaus featuers. I just loved using it. Of course there are many tools which can be used to deliver same kind of end results. But the process of creating using Tableau is just wonderful.
The final key with Tableau is the possibility of endlessly refining the data. So you can star with basic dashboard view, but you can narrow it down to the things that really do matter. It's not a dashboard, it's a data discovery tool when used by experienced analyst and great fun for not so experienced guys too. If we compare it to other popular similar tools like QlikView.
Btw. Many of QlivView dashboards are just those top results of Google Dashboard search.