As I don't see too many answers which are in favour sparkR I just want to mention that as a newbie I started learning them both and I see that sparkR api is more closely related to the one I use with standard scala-spark. As I study them both I mean I want to use rstudio and also scala, I need to choose between sparkr and sparklyr. Learning sparkR together with scala-spark api, seem's to be of less effort than learning sparklyr which is much more different at least in my perspective. However sparklyr appears more powerful. So for me it's a question of do you want to use the more powerful and commonly used library with more support from community or do you compromise and use the more similar api as in scala-spark that is at least my perspective on choosing.
