Hello Igor,
as Antoine pointed out my original answer was on the positioning of SAP Predictive Analytics as an alternative to a fully and manually developed predictive project.
As per your latest question:
So, i guess for people that come from 'R world' it might be an option to use R during 'development' stage and then re-implement the ultimate solution using native APL/PAL functions for 'production' stage. Would you agree on that?
Well, I don't fully agree: why would you want to develop in R and then re-develop the same functionality using the HANA libraries? I agree that R can be a good way to learn how to build and deal with predictive algorithms (and reuse what you already have built) but once you are confident with that I think that you might want to start developing directly with PAL or APL if R doesnt's statsify your performance requirements. Moreover there is no guarantee that the results you get with one language will exactly be the same with another language.
As a side note, if you prefer to work in R, please notice that SAP Predictive Analytics 2.3 can execute R algorithms both locally on your workstation (no need to have an HANA server) or from the HANA server itself. In both ways, you define your R function and then use it in your project as a simple drag&drop components of the workflow.
Best regards
PPaolo