OK, here are some facts.

Those that have carbureted engines (O 320/360) and turn on carb heat
see a much greater rise in inlet air temp since the air is heated by
the exhaust pipe. 

That is not correct.  They will see a much smaller IAT rise in temp
than 100 degrees.  Try it.   I have.  In my carbed engine, full carb
heat will result in a 50dF rise--maybe.   That's not close to 100
degrees and one should remember that the effects of IAT are not linear
on detonation margin.
 
What is the large margin that has been reduced a little?  How is it
related to Compression Ratio?  We need facts, not generalizations.

If you are interested in facts, then it should be measured, not guessed
at.  If those of you doing this have not taken an engine to a
computerized test stand to accomplish this, then you are guessing. 
There are several factors in detonation margin.  If we remove the fuel
factors, we are left with IAT, compression ratio, and CHT as major
players.  Using higher CR AND higher IAT are both going the wrong way. 
There is a neat little graph of this in Taylor you can look up.  It is
pretty impressive how quickly the changes occur.

Walter,

 

The only facts here are that your engine sees a 50F rise in carb heat temp, I will measure my heater air temp and lower cowl exiting air temp and get back to you on that one.  The other is that we all know the fact that higher CR and higher IAT gets one closer to detonation.  Please don't tell me that a 8:1 CR  IO 360 with a turbocharger that raised the inlet temp 100F is going to detonate running ROP.  How about a supercharger that delivers 40" MAP to a 7.5:1 Lyc IO 520?  With no intercooler doesn't the inlet temp rise 100F or more?

 

Who is Taylor?