Perplexing

This from B&H:

Samyang XP 85mm f/1.2 Lens for Canon EF
You Pay: $899.00

Rokinon SP 85mm f/1.2 Lens for Canon EF
Price: $999.00
Instant Savings: -$350.00
You Pay: $649.00

$250 just to rebrand the lens? Or has Samyang upgraded this lens? Would any owner/renter of this lens care to comment on their impression of either version?