Samsung has announced the Samsung Gear S2, its first round smartwatch.

The watch is actually being offered in three distinct models, with the standard Gear S2 being the flagship device. The other models include the Gear S2 Classic, which has a more familiar and timeless watch design, and the Gear S2 3G, which offers built-in connectivity. In this comparison, we're pitting the Gear S2 3G against the Gear S.

The Samsung Gear S is a watch that's also a phone. Although it still needs a Samsung phone to make most features work, the Gear S packs Bluetooth 4.0, 802.11 b/g/n Wi-Fi, 3G multiband cellular (not 4G LTE), and even a SIM-card slot, meaning it'll let you answer incoming calls via a built-in speakerphone or connected Bluetooth headset.

Similar to how the Gear S lets you place calls and texts without being tethered to a phone, the new Gear S2 3G watch has its own embedded 3G e-SIM card, which allows you to place calls, text, and slurp data without a phone. So, if you're the type who wants to dial out from your wrist, you'll want to look at either one of these devices.

To help you decide which is best, we've explained below how they differ.

The Gear S2 3G has a circular screen, rotating bezel, small profile, and home and back buttons. It'll be available in a dark gray case and matching band or a silver case with a white band. The Gear S2 3G is actually the bulkiest of the three Gear S2 models. It weighs 51g, for instance, and has the following dimensions: 44.0 x 51.8 x 13.4mm.

The Gear S weights a bit more than the Gear S2 3G, coming in at 67g. It's also bigger in general, with the following dimensions: 58.1 x 39.9 x 12.5mm. The 2-inch curved AMOLED screen sits flush with the wrist, though, diminishing its scale. It also has a removable strap, should you want to swap it for a replacement.

It's hard to say which device would theoretically win this round, considering their designs are so starkly different, and your final opinion would be largely based on your preference of a circular screen or curved screen. But if size and weight are your main concerns, the Gear S2 3G would be the device to get, as it is much more portable.

The Gear S2 3G has a 1.2-inch circular AMOLED (360x360-pixel resolution) display, whereas the Gear S has a 2-inch super AMOLED capacitive touchscreen (360x480-pixel resolution) display. The latter watch therefore has the larger, more pixel-packed display, but it's not circular, and many people prefer their watches to have circular displays.

We can't comfortably deem a winner for this round, as it's all down to opinion.

The Gear S2 3G is powered by a dual-core 1GHz MSM8226 processor, backed by 512MB of RAM and 4GB of internal storage. The Gear S has the same specs on paper, so it's a tie between the two (in terms of power, at least).

The Gear S2 3G features support for 802.11n Wi-Fi, Bluetooth 4.1, NFC, and e-SIM. An e-SIM is basically an embedded version of a SIM chip currently used by most smart devices in order to register and work on mobile networks.

The Gear S features nearly all the same stuff - except it has nano-SIM instead of e-SIM. Both devices therefore have built-in connectivity and can place calls and texts and slurp data without being tethered to a phone.

But it's worth noting the Gear S doesn't have NFC for mobile payments and the like. Due to that, and because the Gear S2 3G has the latest SIM technology, we're leaning toward giving this round to the Gear S2 3G.

The Gear S2 3G has a 300 mAh Li-ion battery and magnetic wireless charger. The Gear S has the same battery and comes with a regular charging cradle. We're a fan of wireless charging, so Gear S2 3G gets this round.

Both the Gear S2 and Gear S run Samsung's own Tizen-based wearable platform. So, this round is a tie.

The Gear S2 features a range of sensors, including accelerometer, gyroscope, ambient light, barometer, and even one for tracking heart rates. It also has an IP68 certified dust- and water-resistant rating.

The Gear S2 also has a rotating bezel and two buttons (dubbed Home and Back), which users will be able to take advantage of in order to navigate and quickly access notifications and apps.

As for the Gear S, it has all the same sensors that the Gear S2 packs - as well as ones for proximity, compass, and UV light. It also has a IP67 certified dust- and water-resistant rating, but that rating isn't as good as IP68.

The Gear S has a home/power key too, though its at the bottom of the display. You have to swipe up on the display to view apps, and swipe down to go back to the main screen. The watch relies on gestures and the home key for navigation, which we think isn't as handy as the Gear S2's rotating bezel.

We're thinking this round should go to the Gear S2, but it's not immediately clear, so we'll call it a tie.  

These smartwatches are pretty similar. The Gear S2 3G is the newer of the two, smaller in size, and uniquely features a circular screen, wireless charging, NFC, and e-SIM. The Gear S on the other hand is a year old, much bulkier, and lacks of NFC. It does have a large, curved display however, which some people might prefer over a smaller, circular screen.

Again, both devices feature built-in connectivity and the same power, Tizen software, and battery life. In other words: you just have to decide which design you prefer and whether NFC and wireless charging are deal breakers for you, as those are the most noticeable differences between the two watches.

If we had to choose though, we'd say go with the latest Samsung watch.