UPDATE:
I put 100 rounds of 124 grain 9mm through my Shield tonight. My groups were a lot better this time around. I used both isosceles and weaver tonight and shot at 7 yards and 15 yards.
I don't know if it is just in my head or factually true, but my groups were better today with 124 grain 9mm, as compared to the 115 grain 9mm I normally use at the range. I'm sure at 7 and 15 yards, the 9 grain weight difference wouldn't affect accuracy too much. I just wanted to point that out before talking about today's range trip.
The target type I used is posted below. I did not have too many rounds "fly" too right or too left, within reason. My groupings were smaller than an adult male's size hand, with the majority of them within the size of an adult male's fist. I did have an occasional flyer, but those occasional flyers remained within the 5 ring at 15 yards. I used the target's head for 7 yards (if I used his body, my rounds would have hit the range's floor). My 7 yard shots all landed within the 10 ring, except for 1 or 2 shots that hit the target's trachea.
While shooting isosceles, I realized I wasn't locking my arm enough the last time I went shooting. I made sure I locked it more this time, and my groups were a lot better. I can safely say I feel very comfortable going back to shooting isosceles like I do with my other pistols. I still shot weaver as well, and there wasn't really much of a difference between my groupings and both stances. I did find shooting the isosceles a lot more comfortable.
This time around, the major difference between my groupings wasn't horizontally, aka windage issues. The distance between my rounds was now more so a vertical, aka elevation, difference. I just have to make sure I don't accidentally push down on the firearm in anticipation of recoil, and work on aligning my sights in a vertical fashion more quickly. Regardless, I feel very comfortable carrying and, if necessary as a last resort, using my Shield in a self defense situation. As I mentioned in previous posts, the most important thing I can do is practice, practice, PRACTICE! I'm still adjusting to shooting a small, single stack firearm as compared to my duty sized, double stack pistols I normally shoot and carry.
...Thankfully, the 1,000 rounds of 9mm I ordered was delivered to my house today and should help!