HardwareI've found it relatively cumbersome to carry Glass around with me at times, since they don't really fold up like glasses into a smaller form factor. The Glass case is a fairly durable bag with a glasses case reinforcing the bottom of it to protect the screen portion of the device. Generally it fits on the head well, but in inclement weather electronics and heavy rain seem like a bad mix - especially while it's on your head.
I've read that some folks have had durability issues even with the case though, often through the frame snapping outside of the reinforced part of the bag. I haven't had this issue yet. A smaller number of users have had atmosphere related problems that resulted in the foil in front of the view melting or burning away. It should also be noted that Google has been replacing devices with these issues under warranty.
Battery life is good if you aren't using it heavily (after getting used to it I generally doubt you'll use it actively); it can last the better part of a day with occasional use, but maybe only about 3ish hours if you're really using it for things.
I will say though that as a person that alternates wearing glasses and contacts, I have a lot of problems with the framed form factor behind Glass. When I wear Glass as a user, it's on days that I have to wear contacts, so for me seems like a bit of a nuisance - like I'm going through extra work to put on glasses in the morning. It's a little thing, but something I definitely notice each day.
SoftwareAs a user I really love the interface that Google made for Glass. I think its effortlessness in use between voice commands and simple swipe controls makes this product as simple to pick up and use as the iPod with its wheel controls. Although it's still not fully flushed out for application installation and customization, it's still getting updates pushed out (I started with their XE4 updates and they've pushed updates to XE7 at the time of this writing). The timeline setup of glass was very functional for the basic capabilities, but they've been adding features over time too (in XE7 they incorporated web browsing to a light degree). There's still no concept of a Google Play Store like in other Android devices, but with their updates it's not too far away.
Living in suburban Maryland, I haven't had much occasion to use the Navigation features of Glass (driving with it would probably be considered illegal), but with the walking tests I've done it's been pretty convenient. I think it would actually be a less distracting way to drive than my phone running GPS directly, but c'est la vie.
DevelopmentGlass runs off of Android 4.0.4 [Ice Cream Sandwich] and the Mirror API is a subset of Google's web services. The sample Java project available was originally written with Google App Engine, although it was later generalized to a set of Java Servlets (haven't downloaded that one; I kept using the GAE version). The Mirror API I downloaded used OAuth2, and has some usage restrictions right now (it's been a pretty generous limit; I'd really think if you were bumping up to the limit you're probably going to annoy your users). I played around with it and some of Google's other services - mainly Calendar and Drive - and got a little annoyed with the OAuth2 and 3 support differences (The Mirror API available for download was an earlier version than the other APIs at the time), but I got around it without too much trouble.
I loaded a different launcher onto Glass (learned about this via the Google I/O YouTube video), and hooked up a mini wireless Bluetooth keyboard, which was fun although the constant Launcher asking of Android really reduces the experience of Glass. I do look forward to a future XE firmware update making this a little less bothersome. However, I will also say that Glass's custom launcher has really given me a new appreciation for what launchers can do. It's the next thing I really want to try tackling with Glass/Android when time allows (A lot of the API stuff I did for Glass was in June; July I didn't have as much free time).
I haven't rooted my device yet - to be honest I don't really know what it'd offer me. I get some people hack Glass and stick Ubuntu on it or something else, but to me it seems like you're doing it more because you can rather than because it's practical. Or, maybe it is practical for some, but that brings me to the last section of this write-up.
UsageWhen I first got it I tried wearing it every day at work to see if I could get comfortable with having it on. I'd say nowadays if I have it on, probably about 60% of the time I forget about it. However, the other 40% of the time I'm acutely aware that it's on my face, and it seems fairly distracting all around. Now, I got the "Sky" color so it does stand out more, but I notice that when I talk to people and it's on, it distracts me by lighting up, or distracts the other person just for being on my head. It's gotten to a point that when I talk to people I usually perch Glass on top of my head to have a conversation. Because for a conversation I prefer a mutually comfortable conversation.
This perception of Glass may change in the future with consumer saturation, but it's a really distracting factor - at least for me.
I'll say I also don't have it on nearly as often nowadays. Partly because it didn't have much to offer me in everyday use - though I get email it's usually nothing I need to read, and when I'm at work or home I get a toast notification anyways off my desktop. Otherwise I'm either driving (again illegal) or running errands or hanging out with people. There's a level of convenience in that I suppose, and the quick hands-free photo/video taking is a really powerful feature, but it doesn't fill a huge void for me. Weekends it usually sees some more practical use, but there's never the "need" to wear it.
The other reason I use Glass less is that I recently purchased the Pebble at Best Buy. It's a "Smartwatch" that I think can be compared to Glass fairly powerfully:
|Google Glass||Pebble Watch|
|Cost: ??? ($1500 dev preview)|
Speaker/Microphone: Yes (can answer calls)
Convenience to Access: Yes (Head)
Discreet: Varies (much on the size of the crowd)
Connectivity: Bluetooth, Wifi
Direct Interactivity: Voice, Gestures, Accelerometer
Offline capabilities: Camera/Video, Watch
Battery: 3 hrs-1 day
Speaker/Microphone: No (But with Call Notifications)
Convenience to Access: Yes (Wrist)
Direct Interactivity: Button Controls, Accelerometer
Offline capabilities: Watch
Battery: 4-7 days
To me Glass and Pebble are very similar devices - personally I think Google could easily and effectively map Glass's interface onto things like a watch or car console and bury Pebble as a company if they wanted to (and if they aren't looking into right now I would be shocked). But right now Pebble has won the short term battle for me as far as usage goes. Its price point is low, its battery life is never an issue in daily use, and it doesn't offer anywhere near the same level of distraction in conversation during day to day activities.
That being said I should also underscore that Glass is a beautiful idea, and it does shine in use cases like events and city environments. Glass's navigation while walking was a great way to not look lost and to pay attention around you, and for recording things while doing things (like enjoying fireworks or a concert) is an absolute delight that cannot be understated.