I've just finished a longish review of Samyang/Rokinon T-S 24mm f/3.5 ED AS UMC Lens. It's as much about how and why I find such lenses so useful as it is about detailed lens performance ...sorry it's not one for the detailed MTF fans ;-)
Hope it's of some interest to people considering the lens
http://www.northlight-images.co.uk/reviews/lenses/samyang24ts.html