The Gear S has 512MB of RAM and 4GB of internal memory. That lines up with its smartwatch brethren: the Moto 360, along with other Samsung and LG watches also come with 512MB and 4GB of internal storage.
There are a whopping seven sensors in the Gear S: Accelerometer, Gyroscope, Compass, Heart Rate, Ambient Light, UV and Barometer. That's quite a lot more than both the Moto 360 and LG G Watch R, though it's not as many as the Microsoft Band (which has 10 sensors).
On the connectivity side, the Gear S has Bluetooth 4.1 to connect up with supported Samsung phones. But it also has standalone Wi-Fi (b/g/n) and a Micro SIM slot for use with 2G and 3G networks when you're out of Bluetooth range.
Calling and texting
While driving and using the Gear S as a phone, friends could hear me very well with my hands on the steering wheel - about a foot away, give or take. It ended up being pretty handy going hands free. I even used it to make calls while typing with no huge audible issues on either end.
While doing chores around the house like decorating for Christmas or doing laundry, I would call people to get a sense of how well they could hear me. Background noise wasn't too loud and when my arm was at my side while walking, it sounded like I was just on speakerphone - a little far but not inaudible.
I can also see it being useful when I'm cooking, though I'd be afraid of getting the watch dirty. However I can't see myself using the watch to call people in public since it's pretty much a speakerphone on your wrist - meaning everyone can hear your conversation. You can connect a Bluetooth headset which will pair up with your Gear S, but what's the point of adding another awkward device to your body when you already have one?
Texting is also a nice feature. Though the keyboard is an itty bitty thing, it's very intuitive. Aside from "how now Beyonce cow," the auto-correct was helpful making the texting process quicker. Ultimately, I can't see texting on a small smartwatch being that great. After all, you're typing away with one finger which makes the process pretty tedious. I will say, it is nice for quick little messages.
It's almost like Samsung knew this because there's a character cap for each text message. You can use your voice to dictate messages but it cuts off around 10-15 seconds depending on how fast you're talking. There are quick pre-written responses you can choose from though, if you're in a rush.