Upgraded from my series 3 aluminium, fantastic watch. The gold colour is very eye-catching especially paired with the milanese loop. Always on display is a very convenient feature and easy to see even in full sunlight. New blood oxygen sensor is great, just wish they activated the ECG in Australia. Charges much quicker than previous models, and the new watch faces are nice. If you're looking for better screen scratch resistance the SS version is better than the aluminium as it has a sapphire glass on the front. Speakers are a lot louder too compared to the Series 3. Overall great watch for anyone and a perfect compliment to iPhones.