Too complicated for the average user.
That's debatable.
Does the *average user* even care?
We're on the development mailing list, after all,
so there's a lot of bias towards the power user side.
It should be visible when you click the "Install" button.
I agree that the current placement makes the source dropdown
not very visible and easy to miss. I was thinking if having some
kind of combo-button (i.e. button + dropdown) would be a
better option - something like:
+ ------------------+---+
| Install | |
| (From Fedora RPM) | v |
+-------------------+---+
This would make the selected source prominent
and allow to easily switch to a different one.
Either way, this is all a UX discussion, and with
GNOME's take-it-or-leave-it approach, I fear
we'd have to patch gnome-software to achieve
something like the above, which would probably
create a lot of maintenance burden.
A.FI.