Samyang corporate site says old and new are same optically, so ignore the "HD" part in spite of so many Ads claiming it is improved and sharper.. New version adds removable hood, that is only difference per Samyang, Inc. I just ordered the Opteka New version for $210. $30 less than others (i.e, Samyang HD) at this time. With the lost Amazon Gift Card we found laying around, it was just 185.
UPDATE FYI: Everything I read up until buying, said all these were made in S. Korea. Samyang makes such a statement as well. My Opteka just arrived yesterday and the box reads Made in China. Somewhere (Facebook?) I found Opteka stated that they are now making there own Lenses, no longer relying on a 3rd party to do so. So, this is the one exception. I expect it to perform just as well as the others, as they are identical and I expect Opteka to license the total technical ability of Samyang.
Quality of appearance is excellent, fine finish and feel to the iris and focus rings. Even the packaging was impressively sturdy. The plastic tray the lens fits in is very thick/sturdy. The pouch is high quality too. It seems to deserve its reputation for a "Solid Feel". I hope to shoot with it tonight for the first time. (Played with it in the living room - quite impressive!).