Just got an Infinity 25HNA936+FE4ANF006. Thanks to all for the hundreds of relevant posts. My only regret is I didn't get a Coleman bid :-)
A preference is an always-on low-fan with variable speed as needed. The always-on low filters and evens out the temp, the auto provides the boost as needed.
Something that is not at all clear is the performance of the system when it is on the low, always-on, fan setting. This setting was recommended by another user, but he couldn't answer the questions: 1) What happens in the heat cycle needs more performance? Does it bump up the speed, or turn on the auxiliary strip, or just underperform until equilibrium, or? 2) What happens with the outside unit in the low on during various demands? Carrier seems a bit mum here.
I can also second the "screen the installer" advice. But companies seem to put their best performers with good communication skills at the bid end. At the install end (this has also happened with electricians, window install, etc) you get what you get and mistakes are made. I now have ductwork that is not as agreed.
Thanks! (2nd try, 1st post didn't go through)