As has been said, for the money, it's a great little lens. Small, light, sharp enough and plenty wide for most on FF. I have to admit that I haven't used mine on FF - I use a Sigma 12-24 and 24-70 for those lengths now but I have used it a lot on 35mm film (effectively the same as FF) and Dx.
The only real thing to be aware of is the barrel distortion at the wide end - horizons are best kept in the middle of the frame! It's still a little barrelly at 35mm but not as noticeably, so horizon placement isn't as critical...
It was marketed under the Cosina and Vivitar brands, possibly more - the only differences are the names on the caps and side! Last time I saw one on a dealer's shelf, it was under £100 - excellent VFM.
(I actually still own mine - not valuable enough as a trade in! It's currently on long term loan to a friend who enjoys it as much as I did (on Dx).)