I am happy to say that my 42 Black SS work as expected from 8 Jun. I use it everyday, I treat it like any other normal watch. I didn't torture it, but take no special care either.
I choose this one because I love it's black look. Nothing to do with the DLC coating. In fact, I know nothing about DLC coating until I buy this watch. However, it proves that this coating works very well (at least on my watch).
In the last 10 days, I moved to a new place. I move at least 100 boxes, some of them are quite heavy (e.g. book inside), and plenty of metal items. So far, zero scratch, not a single one on the screen or the band.
In fact, 2 weeks ago. I saw a tiny silver scratch like line on the band. I believed that's a scratch, but I don't really care about it. And now, that line is gone. So, it's actually the band scratch something else, and just the metal residual stick on the band. I didn't do anything to it, and it's now back to normal. There are plenty of contacts between my watch and the surrounding objects. So far, nothing can cause any damage from normal usage.
In terms of the function. I know what I was looking for before I bought it. All I need is just an extention of my iphone. So that I don't need to carry my phone with me (inside my home), but I won't miss any call, and I can leave my phone at silent mode all the time. This is the primary reason that I get the Apple watch. And it work really well in this aspect. The only problem so far is that about once a month, my watch will not able to connect to the phone via my home wifi network. Since I expect it will work, so that I won't check if the red lost connection icon is there (until I really use my watch to do something). Therefore, it may actually make me miss call in that few minutes to few hours period. Luckily, this still works better than without the watch. Also, the fix is so simple, forget the network on the iphone and join it again will fix the issue straight away. I can't miss call because my job's nature. So that when I am on duty, double check if the watch is connecting to the network properly when my duty start, still much much better than I must carry my phone all the time, and must set the ringer as loud as possible (which may wake up my baby at mid night). Yes, I may on duty at mid night, all I need to do is sleeping and able to receive calls from my company. So, I can now just wear my watch and go to bed. The vibration is not that strong, however, it's a very effective way to wake me up. I never ever miss anything at mid night. And I can have a quick look to make sure it's the company calling me, but not any spam call. Which is a bonus.
The digital touch is good fun, but not a killer function. It make me very easy to call my wife or daughter (inside my home). I can tap on it and they know I am looking for them. Of course, they can do the same thing as well. So no one need to shout (again, this may alert the baby), and no one need to shout from one floor to another (this won't work anyway

). However, if I need to pass more info to them, it's still easier to send them a voice message (e.g. ask my daughter to get me something from her position to mine). Drawing on the watch is more time consuming, and won't work better than a voice message (apart from it's more fun).
3rd party apps still the weakest point on the watch (especially the very long loading time). Hopefully the Watch OS2 will make it better (AFAIK, it's much better in WOS2 because the 3rd party apps can work without the iphone). However, the notification / glance for 3rd party apps works quite well in most of the time (e.g. the watch can alert me when there is a delay / gate change for my flight). In fact, this is what I need from the watch. If I need a full function app, I still prefer to use my iphone (I am not sure if I was affected by the long loading time on the watch, so that I don't want to use any 3rd party apps on the watch. Or it's really as simple as the watch screen is too small for any relatively complicated interaction, so that I prefer to use the phone).
Since I use my watch, I learn and actively use voice control and dictation. I never use this function on my phone (before I get my watch). And my comment is that which make some simple control much easier (but can't replace complicated control), however, the accuracy is not very good. It's about 99% accurate for simple function like set an alarm, but only 80% accuracy for dictation (Cantonese). Also, the "Hey Siri" function only works 90% of the time, not high enough for a device that heavily rely on this function.
Navigation is another function I used. If Siri works, then everything is simple. I don't even need to pull out my phone. However, since the accuracy of the dictation is not that high. So the overall success rate for a "smooth experience" to use this function is only about 50%. Another 50% I still need to pull out my phone.
There are only few watch faces to choose. However, I don't need many, I only need one which serve my well. Luckily, the modular face works well for me. I can have my roster, local time, date, UTC, timer, alarm, all these on a single watch screen. It seems the Watch OS2 will further enhance the modular face, which is a good news for me.
One of the "better than expected" area is the battery. Usually, I wear it when I wake up, and charge the watch when I sleep. For most of the time, the watch still have 60%+ battery when I recharge it. The most demanding case for me is that I was suffered from an unscheduled overnight at somewhere else. I don't have my charger with me. So I wear the watch for more than 30 hours. Without any power saving action, the watch still has 16% battery on the next day when I back to my place. Not a lot of buffer, but surely enough to handle something like this. And next time, I can turn the watch into power saving mode when I am in the hotel room, which should save lots of battery, and make the watch have plenty of juice to work on the 2nd day.
To sum up, I will say the watch works well so far. As long as the user know what (s)he is buying. The watch should works as expected. However, it's definitely not a must have item for most people (the "must have" level is much lower than a smart phone). Also, as a toy, it's not much to play around (at this moment). Will I ditch the Apple watch and go back to my Rolex? NO. However, can I live without it? YES, but just less convenience.