S,
You will just never be able to tell the difference.. Unless you are an idiot and run your IntelliFlo at full speed all the time, there is just nothing to gain by using sweep elbows.
In theory, the reason to have a VS or VF pump is so that you can run it at a low RPM and still have a good amount of flow.
I have a rent house where I redid the pad using sweep elbows. I saw zero difference in how the overall system worked.
Thanks,
Jim R.