It is very important to understand that whilst I stated I would buy a Nikon Lens – that is a personal choice. And one which comes from my bias AGAINST third party lenses, generally: and having used many (third party lenses).
It is very important to understand that (quality) third party lenses can produce very good images and will not (should not) necessarily inhibit Photography or the quality of it - 99.9% of the time.
WW