The 16i isn't the best unit for capacity and efficiency. Often, the unloading scroll isn't the greatest either but looks like in the XR15 5 ton, it is much better.
Another thread asked about the 16i vs a Rheem RPRL. I pointed out that the RPQL single stage blew away the 2 stage in everything but SEER. I looked at the XR15 and XL15i heat pumps, they weren't as impressive as the Rheem. Key is finding the best match.
Of course, we don't know what furnace the OP is getting. Hopefully it isn't using an existing one! Then he'd be lots lower in every category.