Part I: 1550 sq ft "ranch", 60% very high vaulted ceilings, 40% flat 9-foot ceilings. Located in Eugene Oregon, built 1994, "Super Good Cents" energy certified. Currently has a 2-ton Janitrol heat pump, and a 50,000 BTU Day & Night 80% gas forced air with a 1/3 HP blower. West side of house bakes in the afternoon in the summer.

No problems heating, system moves plenty of air, no excessive cycling.

Cooling has been a different story since Day 1. If it's 90 outside, the hp has to run continuously to maintain 80. If it's 100, it can't get the house under 85.

So I'm talking to contractors. Nobody has done calcs. Based on my input, and their agreement that the existing D&N furnace and air handler (and 30-Amp circuit) can handle up to a 3-ton HP, they're recommending the 3-ton.

Does a 3-ton sound outrageously oversized for this house? They say it's "slightly" oversized but nothing to worry about.

Part II: Goodman 13 SEER vs. Similar Other Brands. I've been leaning toward the Goodman due to price (duh!). An equiv. Lennox and Trane are ~$800-$1000 more. In the professional opinions of all here, is the initial lower price of the Goodman really false economy, given that I will probably live in this house for at least the next 20 years?

Thanks for any input.