Even if you would not intend to activate the built-in cellular feature, other reasons why you may prefer to consider buying Apple Watch Series 3 (GPS + Cellular) include that (GPS + Cellular) models:
- Have double the storage capacity of GPS-only models.
- Have a ceramic back (instead of a composite back).
- Are compatible with Apple's recently announced AirPower wireless charging mat, which is due to be released next year:
- Include options for Stainless Steel and Space Black Stainless Steel cases (all GPS-only models are aluminium).
- Stainless Steel and Ceramic (Edition) case models have a sapphire crystal, which is more scratch resistant than Ion-X Glass.
Apple Watch - Compare - Apple
Apple Watch Series 3 - Apple
About Bluetooth, Wi-Fi, and cellular on your Apple Watch - Apple Support
How to use your Apple Watch without your iPhone nearby - Apple Support