Hhmmm....The PT-911 (a medium-frame pistol,by my recollection) is a somewhat smaller/lighter version of the PT-92, -99, & -917, although their magazines aren't compatible with the 911. It's an all-metal construction; the gun has been discontinued by Taurus. 3" groups at 16+ yards with your other handguns (?) is excellent, especially for a self-described newbie---so, there's no point in speculating about lots of reasons for a spread-out groups that aren't related to the firearm.
I've never had any significant problems with any Taurus products (just lucky, I guess), and I've shot a number of them in different models/flavors. I've found them to be as accurate as I am--again, I've had no significant problems.
I see you've traded the Taurus for another handgun. If you come by another Taurus/Taurus-Family product, you might consider participating in the Taurusarmed.net Forum. The folks over there are knowledgeable about the products, and obviously aren't as inclined to bash the Taurus line as are folks on other forums. Even though I'm banned from that forum (my request, over a "political" difference), I have to say in general that they're pretty nice.--Patrice