I change my task systems fairly often. And I kind of think it is a good thing.

My experience is that what works well for me is based on the amount of things that are going on. And where I feel like my current complexities and pressure are.

When things are going well and I have a lot going on OmniFocus works really well for me.

But when I have to hit the breaks and simplify Things + NotePlan often works well.

Other times it works better to just use paper.