I ended up installing ubuntu touch stable today to my nexus 5 (hammerhead) with
https://github.com/MariusQuabeck/magic-device-tool

and I got ubuntu 15.04 (r13) (20170127-093441 / 20160603- )

and if I start the browser in phone it crashes at once. That is pretty bad.

I have noticed that the there is OTA-15 out, but I guess that the magic-device-tool did not give me that version. Or did it, how I can check it ?

And does anyone know if magic-device-tool images will be updated in near future ?

I noticed that there are system images available for the devices that are supported by ubports
Re: Hammerhead on system-image.ubports.com

..but is there some way to make those tar.xz files to .img files that could be used with twrp or multirom ?