Your astrophotos are really spectacular!
Both look amazing, and as you said you have also been shooting the Nikon 105e.
I would love to know how the Nikon did compare to these two other lenses.
Perhaps it is not as sharp for this kind of photography?
I can imagine it is still good though.
Perhaps the new Sigma 135mm 1.8 will be the top option for this application soon.
Anyway - intriguing shots indeed!