The LTE connection will cost you about $10 a month at most carriers, and the LTE model does cost more. There's a non-LTE version, too, if you're not interested in the new feature. Most people probably don't need LTE, frankly, unless you regularly go on hikes or long runs and you don't want to be weighed down with your phone. Still, it's a nice option to have.
For deeper integration with your Android phone, you can give Google's Wear OS platform a try with Fossil's $275 Q Control touchscreen smartwatch. It lacks GPS and support for NFC payments, which is why the Gear Sport is a better fitness-focused smartwatch for Android users, but Fossil's Google Assistant integration and stylish design make it a solid contender. However, smartwatches with Qualcomm's new Snapdragon Wear 3100 processor start shipping in October, so you may want to hold off until we put them to the test.