The inordinate delay that carriers and manufacturers impose on releasing updates of the Lumia firmware can be offset by the installation of the Preview for Developers app. This allows users to install the updates before they’re officially released. Occasionally there are some problems that accompany these, but generally speaking the updates are bug free and stable. The same cannot be said for the Technical Preview.
It has been suggested that the earliest release of Windows 10 for phones is expected within the next few weeks, it will no doubt have a number of bugs and will almost certainly not be stable. Serious battery drain is perhaps the most serious problem cited. Presumably as a result, the head of the programme at Microsoft has tweeted that:
@RoyHansen1 Yes, we’ll have a recovery tool to roll back for all phones that are supported for the preview.