formGroup.get vs formGroup.controls in reactive form - Angular
Just like what you have found, FormGroup.get is designed to access target formcontrol by it's path. And it's more often used for complicated(multi layer embed) situation, which makes it easy to get the target control from multi layer embed form and also makes code clear and easily to understand.
Take below as a example, you can simply access the first element of the embed FormArray by this.form.get('test.0') instead of this.form.controls.test.controls[0]:
this.form = this.formBuilder.group( { test: this.formBuilder.array( [ ['form control 1 in form array'], ['form control 1 in form array'], ... ] ) });
This question is related to: Will using Angular Reactive Forms .get() method in template cause unnecessary method calls like a component method?.
In templates I prefer using myForm.controls.name to avoid the myForm.get('name') function call. If the field selector is very complex, then I would store the field in a component attribute so in the template its access is instant.
In controllers it shouldn't matter too much using one or another.