meg
how do you heat? brand, age, model of furnace or boiler?

I would want Carrier's Comfort series mdl over the Base series model.

of course you are aware you will also require matching evap coil.

you want to compare warranties.

IMO

We have an ~12 year old Carrier 80% efficient natural gas furnace. We do plan to update it, but not quite yet, to distribute the cost some and get a little more life out of it.

York LX series is nice. They have compressor jacket and are very quiet. They have a good cabinet. Its better to upgrade the A/C with the furnace at the same time when possible. I would upgrade to the 14.5 seer model if possible. The equipment doesn't cost much more.

If your electric isn't too expensive, it would make sense to upgrade your a/c to a heatpump. They typically don't cost much more. Then you would have dual-fuel. The heatpump can provide comfy and less expensive heat when its not terribly cold outside (above 30). It can also give extra flexibility incase natural gas gets expensive again. Even if your not a heatpump fan they can be used when above 40 degrees outside. This isn't for everybody but I think its worth mentioning. Heatpumps take some getting used too if your not familiar with them, but you can be glad you have them in no-time.

to set the record straight

depending on model and dealer fairness in pricing, one can expect to pay minimum $500 more for a good quality heat pump over the same model in AC. Usually this also involves installing a new thermostat and outdoor sensor.

the cost of electric vs nat gas matters in helping to make an informed decision of straight AC vs heat pump.

heat pumps are not for everyone or every homeowner HVAC application.

IMO

Thanks for the responses!

Yeah, we did look into a heat pump as well, the general feedback we got was we're far enough north, and the cost of natural gas is such that it doesn't make a lot of sense.

That's about our same rationale with staying at 13 SEER. We use the AC maybe 20 days a year. We have huge oaks and a house that vents well, so if it's below 85 or so we don't need it.

I hear you on replacing both at the same time, but my counter argument is that with the current cost of natural gas it makes sense for us to get a few more years wear out of our existing one, then upgrade.