I received my lock and wanted to add my experience with it in the short time I have been using it. I replaced my U100 with the U400. The install went smoothly without any issues. After a quick update it went into the aqara app quickly. Then into HomeKit without issue. The only thing that I wish it had was a way of saying It was replacing the old lock with an updated lock and it would prompt you to bring in the codes to the new lock. I understand finger prints. But codes would be nice to have transferred over. The lock has performed perfectly and even setup a couple features that I wasn’t using before. Being able to walk up and it just unlocks is a really nice feature, this I think is my favorite upgrade. Great job aqara for a nice looking lock that works very well.
I am really excited to switch out my U100 for the new U400
I’m not sure how Aqara could build in the migration tools you’re asking for, but that’s a great idea.
One thing I was reading the other day is Aqara’s sensor is so good it can tell how fast you’re approaching the door and adjust the opening of it based on your speed. For example, if you’re running to the door it will already be unlocked when you get there and if you’re walking slow it won’t open 20 seconds before you get to the door. I’m super excited about this lock.
Thanks for sharing your experience! I was originally on the fence about the lock but all of these positive posts make me excited to try it out. Does battery % correctly show in the Aqara or Apple Home app?
Everything that I have seen so far, I believe the % shown is correct. I did have to charge my battery at the beginning. I also noted the battery % also shows in the home app. To soon to see if there is any discrepancies.
coming from a Yale Assure Lock 2 Plus this is such a great improvement. I’m glad my experience with Yale support was terrible because it pushed to towards the U400 and so far its been great.
Thank you so much for sharing your experience! 
We’re really glad to hear the U400 has been working smoothly and that you’re enjoying UWB unlocking feature.
Our team has spent 2 years on this project, working hard to make the UWB experience in Apple Home truly seamless and all for users like you.
If you have a moment, it would be awesome if you could share your experience other platform as well. It helps us keep improving and delivering the best experience possible. 
People who replaced U100: could you tell me please if you had to do extra drilling or of U400 a drop-in replacement for U100.
Thanks
Mine was a straight drop in . No adjustments needed. Hope yours is the same.
If you have the U100 or the U50, the U400 should be a clean swap from my experience, no additional adjustments. Hope this helps.
This product is arguably Aqara’s best product in their catalog. I purchased three of these and set them up for the kitchen and both of the bathrooms in my high-rise. Even though I have the G410, that’s also a hub that enables me to adjust the settings for these sensors, believe it or not, the default settings straight out of the box serve me perfectly. The sensors are definitely smart as well with the onboard AI, and they can actually tell and adapt to changes in the environment and whether automations should be triggered or not. You can adjust the settings in the Aqara Home app for the sensors, but to be honest, I do believe straight out of the box most people will be more than satisfied with just plugging in to the Apple Home ecosystem straight and start building automations for it. The finished product has definitely met expectations from me. As I’m sure a lot of people have been waiting for this product to release. If you’ve been waiting, I don’t think you’ll be disappointed at all. It’s quite an impressive product.
That’s awesome to hear it’s a direct swap from the U100. I was worried about having to drill new holes, so knowing it’s a clean fit makes the upgrade a lot more tempting.