Mediavets, thanks for that. That would really save me a lot of money. Is the quality just as good?
This lens is relatively new to the market but many very experienced pano photographers have purchased or tested this lens and are very impressed with it. Some say it is a little more prone to flare than the Sigma. It is an entirely manual lens - with no electrical connection to the camera - but that is no real disadvantage for/when shooting panos, although you won't get lens dat in the EXIF.
I have a Sigma, but I got it secondhand, and before Sigma radically raised their prices, for not much more than half what a new one costs today. But had the Samyang been available then I think I would have got one instead.
You say a few more shots, so it could do a full 360*180 in about 7 shots instead of 5?
6-around plus zenith and nadir is recommended by most people, but it has been demonstrated that you can get 360x180 coverage with 4-around plus zenith and nadir although the overlaps are then rather small.
This thread on the panoguide forum will give you some other opinions/info:http://www.panoguide.com/forums/qna/7448/
Lots more if you're an avid reader:http://www.panoguide.com/search/?s=samyang&field=all§ion=forums