Technically the Gear Live is taller, but that has more to do with the watch's curved-bezel design, and the way that its main body is measured, than any significant size difference. The biggest news here is that the LG G Watch is 12 percent thicker.
The Gear Live uses a brushed stainless steel finish (similar to what we saw on the Gear 2). LG says the G Watch's body is also made of stainless steel, with a silicone band.
If you don't like your watch's default band, both models will let you swap it for a standard 22 mm replacement.
Can't say we've ever used this as a category before, but we thought it was interesting that LG's watch is completely buttonless. Samsung's has a lone power button on its right side, much like the one you'd find on the original Galaxy Gear.
Both watches are water and dust resistant, rated IP67. That means they're able to sit in 1 m (3.3 ft) of water for 30 minutes and keep on ticking.
We're looking at two color options for each watch, though you might be limited to one Gear Live color for the time being. The wine red version (which is really more like lavender) isn't showing its face in the Play Store just yet.
It's hard to put a number on comfort, so I'd take this category with a few grains of salt. But, for what it's worth, Samsung's watch will be 6 percent lighter on your wrist.
No huge difference here, though the G Watch does give you 2 percent more screen real estate.
On smartphones and tablets, the AMOLED vs. IPS battle often comes down to personal preference. But on a watch, that IPS could end up getting the G Watch in trouble, as it won't likely be quite as readable in direct sunlight. For a product that's built around glanceability, that could potentially come back to haunt the G Watch.
Not a huge difference here either, but the Gear Live is a little sharper.
Unlike Samsung's previous Gear watches, which only turned their displays on when you lifted your wrist (or toggled a button), Android Wear watches are designed to always stay on. This lets you pick a favorite watch face, and make it an ever-present part of the device.
In case we didn't make it bleedingly obvious at the outset, both watches run Android Wear. The brand spankin' new platform uses Google Now as its core, so you not only get quick and accurate voice control, but also the context-sensitive "cards" that the service already provides on smartphones. Wear will let you do things like read and dictate messages, ask Google's info database about random facts or trivia, order taxis and even bring up the boarding pass for your flight.
That's a very abbreviated version of Wear's full capabilities (which is only going to grow as time goes by). For more on Android Wear, you can check out our full coverage from Google's I/O announcement.
Android phone compatibility
If you want to buy one of these watches, then you'll need a compatible Android phone, running 4.3 Jelly Bean or higher. You can also check out this handy Android Wear checker (from your phone) to see if it's compatible.
If you own an iPhone, then you're out of luck with these two. But at least you can take comfort in knowing that the iWatch (or whatever Apple calls its rumored health-focused smartwatch) is likely on the horizon.
Heart rate sensor
Speaking of health, you didn't think Samsung would leave its favorite new hardware feature, a pulse monitor, out of the Gear Live, did you? If you're a workout fiend, this could potentially tip the scales in the Gear's favor.
You remember how the Samsung Galaxy Gear and Gear 2 both had cameras? Well, you won't find any of those here.
Battery life is going to be worth keeping an eye on here. Samsung is estimating one day's use for the Gear Live, while LG hasn't said much about how long it expects the G Watch to last. Stay tuned.
No word on the exact model, but LG says that the G Watch has a Snapdragon 400 inside. A Samsung representative confirmed to Gizmag that the Gear Live is running the Qualcomm APQ8026, a quad core chip, that could be part of the Snapdragon 400 family as well. In fact, it's quite possible (if not likely) that we're looking at the exact same processor in both watches.
I suppose it makes sense that Android Wear watches would only need as much RAM as a 2010-era smartphone. So we're looking at a mere (but likely ample) 512 MB in each watch.
As you aren't going to store anything like videos or console-quality games on your watch, it also shouldn't be too surprising that we're only looking at 4 GB of storage across the board.
Both watches are available for pre-order now, and are set to ship in early July. Right now the Gear Live is showing a "leaves warehouse" date of July 8, while the G Watch looks to be pushing out a few days earlier, on July 3.
Considering the Gear Live has a few extras, like a heart rate monitor and a more outdoor-friendly display, I'm a little surprised that it's coming in at US$30 cheaper. Considering how much more advanced Android Wear's abilities are (compared to previous smartwatches), it's nice to see both of them ringing up in this sub-$250 price range.
For much more, you can hit up our reviews of the Gear Live and Android Wear. And for some info on the 800 lb. gorilla in the room, you can hit up our initial coverage of the round-faced (and fashionably late) Moto 360 Android Wear watch.