The Rokinons are very sharp lenses. If you are looking for sharpness then I would go for the Rokinons. But the flexibility of the zooms may be good for you. It all depends on your needs.
Co-President at fourB Productions, Inc.
Blackmagic Cinema Camera, RED Scarlet-X, Panasonic HPX170, Canon 7D
2011 Macbook Pro 17", 2.3 Ghz Quad Core, 16GB RAM
2008 Mac Pro 2.6 Ghz 8 Core, 10GB RAM
AJA IoXT, Blackmagic Intensity Pro, Blackmagic Mini Monitor
Adobe Production Premium CC, Avid Media Composer 7, Final Cut Pro Studio 3