@Django: let me help to clarify a few things on Production vs. Development VM images
- ERP Next can run with Developer mode switched on or off - Development VM image leverages Developer mode switched on by default, as opposed to Production VM image
- bench update command is intended to use for updating ERP Next - it is available regardless the Dev mode switched off or not (however, you are right that the quality of a particular update coming through Bench Update may be different - sometimes it is less then production quality indeed)
- in my experience, bench update rarely crashed the system severely - however, some of the system modules could degrade temporarily if a new release of ERP Next trunk is released with critical bugs missed (this happens from time to time, indeed);
- if you keep saying about bench update breaking your system, you may want to raise special topics on the forum to discuss it as suspicious bugs
The reason why I mentioned that even production VM image is hardly going to be your choice for production mode is that it is a little restricted, anyway. It is good for small companies that do not have qualified in-house IT admins/developers. However, if an organization has its own IT talent, it is always better to deploy it manually on a server that you fully control.
On a separate note, the overall quality of ERP Next builds is one of the key focus areas of the community right now. You may want to review Beta Testing Process to see the active discussion on Beta Testing process and all of the collateral issues related to quality and production risks.