What I've heard about all of the Sigma and SWV series guns is: When they're bad, they're really bad, but if you get a good one, they're wonderful.
S'posed to be a crapshoot, as to what you get.
Some are discontinued. (Wonder why? Duh...)
DON"T buy a used one. (Why's it for sale, again?)
If for some reason you're lucky enough to get a good one, KEEP IT.
On the .380's:
The slide's made of Zantac. (Read: zinc/pot metal. On a Smith? Yuch!)
Some gunrag ran one for 3000 rounds specifically to address concerns of service life. It digested all of them without a hitch, and showed no extraordinary wear. Didn't even slow it down, figuratively speaking.
In conclusion, they're REALLY small, have a very odd mag release system, and seem to be Sellout & Worthless's answer to the Jennings/Bryco market.
If you want one, see if you can test it first. If it's a POS, it's not worth anything. I've never heard anything about their warranty repair track record, but for sure I'm not going to take my chances on one. Seems that when they're bad, you're stuck.
Note: thi is all 2nd-hand, opinion stuff, so take it FWIW.