series 1 is quicker.
series 1 and 0 have the same battery life, as far as i know.
series 1 has a better processor, and is therefor faster in operations.
the first gen (or "series 0") is the original and will not receive the WatchOS 5 update.
Why don't you look into series 2 or 3? They have GPS+GLONASS, and the series 3 even has LTE. They also have a brighter screen AND are waterproof. Series 0 and 1 do not have these features.