Not too big and not too small, and very thin. It doesn't feel bulky in your hands. The fingerprint security feature is very nice but takes a bit of getting used to. If you scan your finger at a slight angle to the way you captured your "print image" it will not work and may take several attempts. I use it with Android Wear and Waze, requiring the phone to have Bluetooth and GPS active all the time. This can drain the battery relatively quick, but with the supplied charging accessories the phone charges very quickly. I tried the wireless charging through my case and it worked with no issues. The only issue I fear is that after a year or so the battery will no longer hold a charge. I usually keep my phones for nearly two years and always need to buy a new battery after the first year. The S6 has a non-replaceable battery. The phone also has no external storage slot. I guess that means it is somewhat waterproof. After transferring all my data (pictures and downloaded documents) from my previous phone the memory is beginning to get eaten up. It is very easy to transfer or backup this data to an external drive through a computer connection...so no big deal. The screen is simply stunning, even in the sun. So far every Galaxy phone I've owned has been the best phone that I've tried, and they are nearly identical operationally. You don't need to retrain yourself how to use the latest model.