As per the rules of the forum, posting facts, not speculation here: Celere are simply re-barreled Rokinon primes (with the exception of the Celere "18.5mm" which is actually a Sigma 20mm f/1.4). Anyone that wants to argue that can come visit my bench anytime for a quick lesson. That said, there's a right tool for every job.
I did a rather thorough test along with some fellow lens geeks that stacked most of the FF/VV primes that fall into the "mid-level" category a few months back. The results live on another forum that I would encourage giving a quick read. The video is rather long since we rolled the same scene about 250 times over 40 something lenses at different T-stops throughout the test. Enjoy! http://duclos.tv/saltvv
-- Matthew Duclos
Los Angeles, CA