I am using Cakewalk Sonar, and I will cling to it as long as possible.
On the other hand, as a "counterpoint" I am using Sibelius, as I am much in classical music, have grown to use notation even when things become complex. It seems to me a close choice to learn using ProTools which allows to switch between a DAW, and the notation program.
But I must say there are so many features in Sonar that I know already now, I'll miss it when I ever deinstall it from my PC in a hundred years.
What I am saying is, you find an alternative to Sonar by the needs and expectations you have. Who is not in classical or film music, or arranging for BigBand, does not need Sibelius really. For me, Sibelius is really as essential as Sonar still is.