Make sure it has good heater output, and even on both sides. Apparently there was some 'baked in' calcium/lime issues (block cleaning is one thought) and over time the stray material plates out on the coolest surface (the drivers side of the HVAC heater core). There is a TSB (14-063) on this and a procedure involving the use of CLR to bust the buildup. In worst case it could need a heater core replacement. This apparently impacted 2012 thru 2014 builds.
Because of the direction of flow, the drivers side tends to clog first. Honda will ONLY address this if there is a noticeable (at least 10' F) differential between sides. That's what they use as an indicator that a selective clog is occurring.
However, I'll tell you that total heat and warm-up time of the cabin is rather slow on my kids car. Thermostat seems to be fine, so I'm leaning towards a developing system clog even if the temp differential isn't evident.