hi Nikolay,
Usually "not for productive use" means that the "Web IDE On-Premise" (SAP delivery is really a few plugins over Oracle's Orion) is provided "as-is" and SAP does not either provide direct support neither "guarantees" about the software they are delivering... it's sort of "use at your own risk" kind of thing - they clean their hands basically if something happens and the counter-part offering is to tie-up with HCP.
Also please remember as soon you utilize Web IDE locally to deploy into your ABAP Mime Rep. you also lack "source control" and "versioning" of your code - you can still work using a "checkin/checkout" style however you should consider to use a source control tool (the HCP counterpart must be using some open source git solution).
Hope it helps,
Dan.
