Been using Microsoft Project for years. It's a great tool. One reason it stays in my repertoire is that I am continually learning new things about it. That being said it's a stagnant product. While Microsoft has grown the market by building and selling Project Server, Project is pretty much the same as it was in the last century. But still with many things to learn about!
I learned recently there are a few competing tools out there that until now I didn't know anything about. Yes, Primavera is out there (too big, expensive, with much legacy) and now that Oracle has bought it who knows where it will go.
Two recent discoveries: OmniPlan by the folks who brought me OmniFocus and OmniGraffle--both of which I use daily. US$150. And a "free" open source project which produces OpenProj which appears to be using Microsoft Project as their design basis.
I also really like and use Risky Project as it changes everything. I consider it "Project Planning 3.0" and has a great future.
I'm going to be experimenting with OmniPlan and OpenProject over the next few weeks in prep for attending the Microsoft Project Conference in September. [I am still a little puzzled why Microsoft, a global player, is limiting the "free" licensed copy of Project Professional 2010 to only those participants at the Conference who are from USA or Canada!.}