Yesterday, Google laid out more of its vision and plans for Android Wear, the software platform for manufacturers like LG, Samsung, and Motorola to build Android-compatible smart watches. And while smart watches like the Pebble, Metawatch, and Samsung's own Tizen-based Galaxy Gear have been around for a while, Google's offering may be the catalyst for the general public to start taking these wearable devices seriously--at least until Apple makes a smart watch announcement. But not all smart watches are created equal, and the approach that Google is taking with Android Wear is fundamentally different from the goals of the Pebble. It's not about hardware or software limitations--Android Wear and Pebble want to achieve different things, and have been designed with different strengths and weaknesses. That means Android Wear doesn't make Pebble obsolete--there's room for both to co-exist, depending on what users want.

But that's exactly the problem--smartphone users don't know what to expect or want from a smartwatch. Those who adopted early smart watches like the original Kickstarted Metawatch have not had the best experience. The $200-250 price tags on these watches are likely as low as manufacturers want to go, but this is still an an early-adopter category. We've been testing the Pebble Steel for a month now, and will be getting the LG G Watch early next month to test. But based on my experience with the Steel (which I like) and what Google and the I/O attendees have shared about the new Android Wear devices, here's how I see the platforms differ.

There are two important differences between Pebble and Android Wear. The first is with software. Both smart watch platforms are meant to be extensions of your smartphone, so you can keep the phone in your pocket while still receiving notifications. The Pebble basically functions as the notifications tray on both iOS and Android--it's a push-feed of new emails, instant messages, phone calls, and app notifications. On iOS, your ability to customize the notifications that Pebble gets is limited--it's tied to exactly what notifications you see in your pull-down tray. On Android, third-party apps let you customize which notifications get sent to Pebble, and app developers don't have to (and aren't able to) program how their apps' notifications are received and shown on the watch.

Android Wear notification-based interface paradigm is similar, but with the advantage of Google Now being thrown into the mix. While Google Now notifications will pipe to Pebble as text, Android Wear pushes relevant information in the form of cards. Everything is card-based, and Google (as well as third-party developers) can customize how their notifications are graphically presented on the watch. It's more work for app developers, but their apps can become that much more useful when the notifications are designed to present the most useful glanceable information.

The other fundamental software difference between Pebble and Android Wear is that the latter is a two-way connection. Whereas Pebble receives notifications over Bluetooth, it doesn't send any information back to your smartphone to let you do anything with that notification, other than to decide if it's worth taking out your phone or not. You can't archive an email from the watch, nor can you tell your phone that you've now read that notification (or bookmark it for later). The only command you can send back is audio playback controls, or tapping into third-party macros to send pre-typed messages. Android Wear, on the other hand, is always in sync with the phone. Swiped away messages go away on the phone, and you can send back voice commands or queries to Google Now and Search. It really is a front-end for Google Now, with app notifications thrown in.

That two-way communication and deep tie between watch and phone in Android Wear leads to the hardware differences. Android Wear devices are built to a higher hardware spec--like Google Glass, they're basically small smartphones with SoC, RAM, and storage. LG's G Watch runs on a Qualcomm Snapdragon 400 with 512MB or RAM and 4GB storage. These are mini-computers on your wrist. Combine that with the use of always-on full-color LCDs or AMOLED touchscreen displays (LG and Samsung, respectively), and that's a device that requires a lot of power. The Samsung Gear Live has a 300mAh battery, while the LG G has a 400mAh battery. Neither have claimed battery life of more than two days--they're devices you're going to have to charge every night.

The Pebble watch, on the other hand, uses Sharp's low-power memory LCD (PDF) for its always-on display, and in our testing can easily run for four days on a full charge on its paltry 130mAh battery. They're monochrome displays, not touchscreens, and only have a resolution of 144x168, but that's totally fine for the purposes of being a notification display. Battery life is where I think most users are going to get hung up on Android Wear. It's something that will undoubtedly be improved in future products, but it's going to be a long time before we see an Android Wear device that can run for a full week before recharging.

Google's competitive advantage is Google Now, with its data-rich knowledge graph and industry-best voice recognition. Even Apple can't compete with that--Siri simply isn't smart enough yet. That's an advantage that Pebble also can't compete with, but is bypassing by targeting a more pared down notifications experience. At the outset of Android Wear's launch, users are choosing between deep functionality on Google's product and the longer battery life and simplicity of Pebble's. That's what I'll be testing for when I get the LG G--whether the benefits of having Google Now on the wrist outweigh the inconvenience of having yet another thing to plug into the wall at night.