A couple of days ago, I had the fun of burning a few hundred Blazer brass rounds with my son. I had one of my "on" days and the PT1911 did a fine job of shooting tight groups at 25 yards. My son, a much better shooter than I am, struggled a bit to keep up with his Mil-Spec. Part of the day's fun was to be able to have two shooters compare the two pistols.
Overall, we both thought the Taurus had a better out-of-the-box trigger. Both of us found the Taurus sights easy to acquire and shoot accurately. I don't have any opinion on whether the heine sights are "better" than the 3-dot sights. For my old eyes, the important part is being able to see the dang front sight. I can do it with both. Both pistols functioned very well despite it being one of those days in SW Michigan where the the weather couldn't decide if it wanted to be below freezing and if it really wanted to snow. The Mil-Spec had a bit of a problem with a magazine, but fired the Taurus mags without problems. At the end of the day, my son was muttering something about getting his trigger to the point that it matched the Taurus.
Both "entry-level" 1911's shot fine in my opinion. I'd give the edge to the PT1911B. If (when?) I decide to buy another 1911, I just might buy a Mil-spec. I already have a Taurus.