@3arn0wl Maybe. But I do not like to promise anything without having information. Up to now, I have no OPO phone and no clue, what to await. So, originally there was only my simple question if I can rool back not beeing forced to throw away the phone after my first try to change OS to Ubuntu. Give me time to try and check. Thanks.

Thank You much for advice. I really have no doubts about Linux. I have used Ubuntu for years, running two servers etc. What I realy doubt is, if mobile phone with Ubuntu will fit with all my needs. Mobile phone i my second office. So, as soon as I receive the phone, I will let know about my experience.
Thanks.

I just ordered OnePlus One phone to check Ubuntu Touch. I am experienced Lixux-Ubuntu user and programmer. In case when something goes wrong or installed UT won't meet my expectations, is there any way to roll back the phone OS back to original Android?
Thanks for reply.Dag.