Sizing advice

I've run a CoolCalc for my house and gotten a load calc of 36k heat, 15,800 cooling. We're in a ranch with a full basement in SW Denver (80127) - about 1600 SF in the basement and 1600 SF on the main floor. I'm replacing a Goodman GMH950703BX, which is a 69k 95% efficient. This has been more than sufficient for our heating needs. We have upgraded LowE windows and R-60 attic insulation. Walls are original 1970s insulation, but have another inch of insulation board under the new siding. We also have a wood fireplace insert that we use for a significant amount of our winter heat - the furnace is mostly used for warming up in the morning on days we leave early and it's not worth starting a fire.

I had settled on a 2-ton/40k unit: https://hvacdirect.com/2-ton-16-seer2-96-afue-40-000-btu-aciq-furnace-and-high-efficiency-heat-pump-system-extreme-series-r454b-multi-positional-217418.html I sent that to HVACDirect for confirmation and they replied with this beast: https://hvacdirect.com/aciq-5-ton-17-5-seer2-high-efficiency-central-heat-pump-system-inverter-extreme-series-r454b-197827.html

Is my CoolCalc really this far off base, or is this just bad advice from HVACDirect? Their "calculator" is pretty simple, nowhere near the detail of CoolCalc, so I'm leaning towards the smaller unit, but would I be better to bump it up to a 2.5 ton/60k unit?