When Runna is worth paying for
You want daily coaching in an app, with sessions sent straight to your watch. You like extras such as guidance on form.
You will open it most training days, and a monthly fee does not bother you. If so, Runna is a good product.
When Run-R is the better choice
You do not want a subscription or another app. You want your own paces, in your own calendar, and a plan you can update.
Run-R builds it from one race time, using Jack Daniels' published VDOT formulas. Base, build, peak and taper are timed back from your race date, for free.
It is also a good way to try a structured plan before you pay for anything.