I am a southpaw and own a Sub 2000 Gen. 2. I really like the rifle but the only minor issue I find being a leftie is that I get a bit of powder coming back at me and hitting me on my right side of the face when shooting. Since I reload 9mm, I have been able to partly remedy this by trying different powders and loads. Some loads are cleaner and friendlier than others and send less back, your mileage might differ.
As far as ergonomics, I have had no issues. Some report that the magazine release gets in the way, but I have zero issues with that.
Hope this helps.
Cheers!
FUDD