i hv the sigma,but for nikon mount.
i loved it for the close range(20cm to focus) and being a marco len, it's very sharp.
it helps if u like to take pic of food,flowers etc.
i dun not hv problem with the paint peelin off and from what i hv seen(a over 1yrs old same len), there wasn't any sign of paint peeling.
the only comestic issue i hv is the front len cover.
it's hard to put it on/off if u hv the hood on.
i suggest u get the nikon 1 for it.72mm...
cos the front cover is like a fixed cover, dun hv the "handle bar" to remove or put on the len