I can assure you that I had a new generation (model sw9ve to be exact) sigma purchased NIB. I never had a failure to feed, fire, or eject and really didn't expect one; it's a good design in that respect. I loved the narrow staggered magazine; most widebody grips are too wide for me but not the sigma. It was a great fit and one reason I held onto it for 8-9 months dry firing the hell out of it. That helped smooth the pull, but the letoff was inconsistent.
A good DA revolver trigger pull is so superior to the sigma, I don't even know where to start especially when the pull weight is heavier on the revolver. A consistent, smooth, even pull is the key to fast DA shooting, not a super low pull weight. Almost any rough, gritty, bumpy trigger pull can be used for very slow fire and still get acceptable results, but speed up the shooting and weaknesses become very obvious.
The sigma just isn't up to precision shooting by most people especially under time and speed pressure. I got a very good deal on the new sigma and really don't like having to put another $200 with the money from selling it to buy another pistol, but that's what it'll take for the better performance I require.
I hope your sigma continues to meet your needs. Mine didn't and I listed the reasons why. It's a great price IF it does the required job.