I decided to get a GE induction cooktop. It has a nice (I think)
amount of power, and decent reliability compared to many other
brands. I had to see the associated literature in a shop in order
to answer my remaining questions. First, the layout of the
burners was not apparent from the pictures on GE's site, which
only show a totally black surface. Second, I wanted the answer
about putting small pots onto larger burners. The layout didn't
look that great until I found the answer to my second question.
GE explicitly states that one can use small pots on large burners,
and since only the pot gets heated. That is something I had begun
to expect, but I wanted to see confirmation of that. (I therefore
don't see why some manufacturers put the smaller concentric
circles onto the cooktop, as if it made some difference.)

One thing I didn't see mention of was a hot burner warning. I
decided this isn't a huge issue, because the burners themselves
are not terribly hot after use. One can touch them and not get
burnt (at least that is the case with the induction burners on my
old Jenn-Air).

I am reminded that I obviously can't use my old Revereware. Has
anyone tried cooking with an intervening steel plate and using an
otherwise unacceptable piece of cookware on top of that?

I think I will go back to carrying a magnet around with me, so I
can check pieces of cookware while I am out and about.
--
Jean B.