In another thread I mentioned that only one contractor had actually taken measurements and inspected insulation etc, then used software to size a replacement system for my house. 4 or 5 others based their proposals on the size of the existing furnace or the size of the house as I remembered it. (Of course, realtors measure the outside of the house, and it was like 1850 sq ft when I bought it, but with 1 foot thick walls the inside is only 1511 sq ft).
Anyway, the guy who did the measurement and prescribed a considerably smaller furnace and AC than the others is a Carrier dealer. In this case, the AC has a reciprocating compressor instead of a Scroll. Should I care about that? From what I read, scrolls are much more reliable.