Smartwatches have yet to really take off, but this holiday season is going to mark the biggest push we've seen from OEMs. Ahead of IFA 2014, Samsung and LG have already spilled the beans on their upcoming flagship watches. Read on, as Gizmag compares the features and specs of the Samsung Gear S and LG G Watch R smartwatches.

Size

LG hasn't yet listed the dimensions for the G Watch R, but the images in this post should (roughly) reflect the watches' relative sizes. We sized them based on their screen diagonals.

Standalone wireless

The Gear S is the first mainstream smartwatch we've seen that can work its mojo without a paired phone. With its built-in 3G connectivity (sorry, guys, no LTE), a SIM card should make the Gear S one of the smartest watches we've seen.

The Gear S can also pair with a phone, but we're still fishing for details on a) exactly which phones it's compatible with (likely Samsung only), and b) whether any features will be disabled when you're using the watch on its own. We'll update when we find out more.

Display (shape)

If you're looking for the G Watch R's killer feature, look no further. This holiday season, LG's watch is going to do battle with the Moto 360 for the hearts of those lusting after round smartwatch displays.

Meanwhile, the Gear S has a curved rectangular display. We haven't yet handled it in person, but it looks like a larger version of the Gear Fit's screen – and I was a fan of its sleek design.

Display (size)

While the G Watch R is going to look more like a classic watch, there are advantages to the Gear S' more tech producty look. Namely, it gives you 44 percent more screen real estate.

Display (resolution)

Both watches' screens should look fairly sharp, but the Gear appears to have the advantage. It comes in at 300 pixels per inch (PPI) and, unless our calculations are off (the abacus is still in the shop), the G Watch R packs in a not-as-sharp 246 PPI.

Display (type)

The G Watch R is using the same P-OLED display tech found in the G Flex phablet. LG says that the screen will provide "stunning image clarity even under bright sunlight." We'll have to wait to see if that's the case, as the first two Android Wear watches had some issues with visibility under direct sunlight.

Software

Another big difference here is that we're looking at Samsung's wearable version of Tizen OS, next to Google's Android Wear.

In previous watches, we preferred Wear's superior voice control and more direct integration with Android apps. But Samsung is updating its platform for the Gear S, so we won't leap to conclusions until we get some hands-on time.

Voice control

It's going to be tough for S Voice to top Google Now for powerful and speedy voice input, but Samsung is saying that we'll see "enhanced S Voice functionality" with the new Gear.

Onscreen keyboard

With the new Gear's (relatively) spacious screen, Samsung is throwing in native keyboard input. The company says that you'll be able to use it to "instantly reply to messages."

On a 2-in screen, it's hard to imagine typing being anything but a cramped experience – but it's also hard to knock the company for giving us the option. If nothing else, it could come in handy when you're in public and don't want to be heard talking to your wrist, Dick Tracy-style.

Though some developers have announced plans to cook something up, Android Wear isn't yet designed for any kind of keyboard input.

Phone calls

Like previous Gear watches, the Gear S lets you make and take phone calls on your wrist. Unlike those watches, though, the call can now take place without any help from your phone.

Android Wear isn't designed for phone calls – at least not yet.

Heart rate monitor

LG's original G Watch lacked a heart rate monitor, but with the G Watch R, the company is joining in on the pulse-measuring fun.

Fitness tracking

Both watches can track your daily steps in the background, as well as log individual workouts.

Water resistance

Both watches give you IP67 water and dust resistance.

Colors

The Gear S will ship in both black and white options, while LG is currently only listing the G Watch R in black.

Swappable band

If you aren't a fan of either watch's default band, you'll be able to swap it out for a different one. For the G Watch, it will play nicely with any standard 22 mm strap. Samsung hasn't mentioned the specifics on the Gear S' band, so it's possible it will require a proprietary Samsung-made one.

Camera

The Galaxy Gear and Gear 2 both had built-in cameras, but Samsung is opting out of that game for the Gear S. As Android Wear isn't currently designed for cameras, the G Watch doesn't have a shooter either.

Battery

Samsung is estimating an average two days of uptime for the Gear S. LG hasn't mentioned any estimates yet – apart from describing its 410 mAh battery as "durable."

No word yet on the charging method for either watch, but we'd bet on the Gear having a small charging cradle, similar to what we saw on all of the other Gear watches.

Built-in GPS

Here's another first for the Gear S, as it has built-in GPS along with turn-by-turn pedestrian navigation, through Nokia's Here service.

The G Watch R will display Google navigation directions from a paired Android phone, but doesn't have any GPS radios built into the watch itself.

Storage

You probably won't need to worry about this, but both watches list 4 GB of internal storage.

RAM

Likewise, we're also looking at 512 MB of RAM in each watch.

Processor

Neither company is getting very specific, but Samsung says that the Gear S has a dual core 1 GHz processor inside. LG lists the Snapdragon 400 for the G Watch R, which probably means the same quad core CPU that we saw in the first G Watch.

Physical buttons

Right now we're working with limited information, but it looks like each watch has a lone physical button. The Gear S clearly has a small home button beneath its screen, while the G Watch R has a faux winder (which we guess will serve as a power button) on its right side.

Release date

We know that the Gear S will roll out starting in October, while the G Watch R will launch in "Q4." That could mean as early as October, but possibly later.

Price

Unfortunately we don't yet know what either watch will cost. If they follow in the footsteps of their smartwatch predecessors, then we're probably looking at something in the US$200-300 range. But with the 3G capabilities of the Gear and the round display of the G Watch, you never know.

Also keep in mind that, unless Samsung partners with wireless carriers for free mobile data, you'll also need to pay for an extra line of wireless service to use the Gear S without a paired phone.

Stay tuned to Gizmag for much more on these two. We'll be on the ground next week at IFA 2014, and expect to spend some quality time with both smartwatches.

Updated on 9/8: correcting the G Watch R's display type (it's Plastic OLED, not AMOLED)