It really depends on how much control you want. The R8 has only two dials, whereas most higher level bodies have three. Three dials means one each for aperture, shutter speed and ISO giving you full control over the exposure triangle. The control ring provides a 3rd dial, I have mine set to ISO.
However, the original R had the same control limitation as the R8 with only two dials and IMO Canon developed Fv mode (which was first seen on the R) to deal with just that 'problem'. If you're not familiar with Fv, check it out. In a nutshell, you use one dial (thumb by default) to switch between setting aperture, shutter speed and ISO and the other (index finger by default) to change the value of the selected setting. Any or all of the settings can be set to Auto (and you can assign a button to return the selected setting to Auto, or to return all settings to Auto). It sounds more complicated that it is. In practice, it's a great solution and now my most commonly used mode on both the R8 and R3.