I have received 2 quotes for a new central air system. The Lennox
contractor offered 3 units - Merit 10 , Elite 11 with scroll
compressor, and Elite 12 with scroll compressor and R410-A
refrigerant. He thoroughly explained the new/old coolant issues and
regulations. He did not at all push the Elite 12, even though it was
the most expensive, and seemed to favor the Elite 11 as the best
value.

The Bryant contractor offered a 10 SEER Freon unit, and an 11 Seer
Puron (R410A) unit, and was strongly pushing for the Puron unit. He
also explained the coolant issue thoroughly.

I am stuck between the Lennox Elite 11 at $2300, and the Bryant Puron
at $2450.
I was leaning toward the Elite 11 due to the scroll compressor, which
they explained was quieter, and had less moving parts to break. But
should I go an extra $150 and get the Bryant Puron unit? (the Lennox
Elite 12 with R410 was pricier than Bryant's equivalent). I am not too
concerned about the SEER. I think a 10 or 11 is fine for my area. The
warranties are the same for each of these units. Would it be better to
save the $150 right now, and take the chance that the unit will be
fine for the next 10 years or so, or should I go with the Bryant
Puron? The Lennox guy and the Bryant guy were like night and day on
their opinions of the new/vs old coolants, as far as the importance of
getting the new stuff.

Another question - how do I know if they did a cooling load study on
my home? They both measured the house. One of them asked about
insulation, and went up to the home's second level and took a quick
look around. Both gave me a complete quote on the spot. From what I
have read, the study sounds more complicated than that. Or are they
able to judge by their experience in the area ( I live in an older
tract subdivision, where lots of the homes are similar, both are local
contractors). They both quoted 2 1/2 ton units, which coincidently is
the sq footage of my house divided by 500.

Any help would be appreciated. Also any input on the quality of the
brands, or is there a better one comparably priced?

Thanks for any help you can provide.