In the first place, your title is wrong. Churches don't use systematic theologies usually. Perhaps you mean schools. In that case you would have to mean seminaries, since colleges don't usually have systematic theology courses, though I have heard of it. If a Bible college does have a course in it, they would probably use Introductory Lectures in Systematic Theology, by Henry Theissen--kind of old, but still good.
As for seminaries, the go to Baptist volume nowadays is Christian Theology, 3rd ed., by Millard Erickson. I took courses from the 2nd ed. years ago in seminary, and now teach Eschatology from the 3rd ed. This is an excellent textbook on the subject.
I really don't know who would use MacArthur's--didn't even know he had written one. But MacArthur is so strongly Calvinist, I doubt that a non-Calvinist school would use his volume.
Just looked at it on Amazon. The MacArthur volume is considerably more expensive than Erickson. That's a consideration for a prof. Seminary students are not rolling in dough.