Features of the XL16i
Durable Climatuff® compressor
Full-side louvered panels
WeatherGuard™ II top
Baked-on powder paint
Corrosion-resistant Weatherguard™ fasteners
All-aluminum Spine Fin™ outdoor coil
DuraTuff™ non-corrosive base pan
Unique mounting of shaft down fan motor
Variable-speed fan motor
Quick-Sess cabinet with full coil protection
Low sound with advanced fan system and sound insulators on compressors (on select models)
Features of the XR14
Climatuff® compressor
Spine Fin™ outdoor coil
Upgraded fan motor
Full-side louvered panels protect your investment
Corrosion-resistant Weatherguard™ fasteners
Unique DuraTuff™ non-corrosive base pan
Quick-Sess cabinet with full coil protection
The above chart has nothing to do with the capacity ( variable speed ) of the condensor fan, that is reference to the compressor, being 2 stage or variable speed compressor.
The XL16i does have a variable speed condensor motor where as the XR has a " upgraded motor " IMO means a standard one speed improved motor, maybe it's quieter or uses less amprege, or better bearings or something.
What you should do before you pull the trigger have whomever quotes a system to you have them give you the AHRI number which will show you the SEER,EER, total cooling BTU. Depending on indoor selection will tell you the true SEER, EER. all those numbers are on paper, not real world situation.
If its slightly more expense ( XL16i ) and your getting more factory standard features and higher SEER,EER and probably higher total cooling BTU, better compressor warranty, quieter, etc. I certainly would lean towards the XL series.
You can also purchase a extended labor warranty for up to 10 years, and some are transferable on both models.