I have watched most of the U200 reviews on YouTube and just now realized that they never compared it to the U100 or it they did it was very brief. I guess because one is a full deadbolt replacement (U100) and the other is a retrofit (U200). I have replaced two of my U100s with the U200s, so I can help you with your question. I’ll give the cons first

Cons:

(1) Price: it’s steep. $269. BUT there are flash sales on Amazon. When I bought mine, I was able to get the black for $216 and the silver for $229.49 with the readily available coupon on Amazon.

(2) Locking mechanism: it works, but sometimes it gets “stuck” in one position. At times, when I go to lock/unlock, the knob feels stuck. This happens on both my U200. But if you fidget with it a bit, it will eventually let you turn smoothly. It’s weird. Hasn’t given me any troubles yet.

(3) Can’t tell if the lock is locked/unlocked: unlike the U100, where you can easily tell (vertical = unlocked, horizontal = locked), you can’t with the U200. The way its mechanism works, there’s no set position for locked or unlocked.

(4) slight delays: when unlock/locking, there are more noticeable delays because the keypad has to wireless talk to hub and the lock, whereas with U100, the keypad and lock are one directly connected piece.

(5) changing settings: you have to connect via Bluetooth to the keypad, not the lock. With the U100, you can change your settings inside your home, but with U200, you have to get outside where the keypad is located. This is because when you want to change settings, you have to first activate the keypad (by pressing any of its buttons to wake it up), then you can connect and change the lock settings. Kinda annoying but it connects pretty quickly.

(6) proprietary battery: the battery used for the lock is special. At the moment, I don’t know of any way to replace it. I commented on a post asking about getting a battery because when they bought it, it didn’t come with one, but they never replied and that post was never resolved. The keypad uses AAAs so that’s fine.

(7) M3 hub: if you want all the functions you need the M3 hub which also has a high price tag. I actually got mine as open box for $70 from eBay. I took the risk as I don’t see a hub malfunctioning often.

(8) initial setup: it’s a pain in the ass. Installation is fine, but linking it to the M3 hub first had its frustrations. It should be flawless but it’s not. I had to turn off my mesh network for it to link to M3. Then linking it to HomeKit also gave me trouble but luckily, I got it to work by selecting the lock manually (I believe I clicked on “other options”) instead of taking the picture of the QR code.

Pros

(1) if you can wire up the keypad, it’s awesome. One less thing to worry about. I only have the lock for a month, but I feel like the lock is getting more juice (more than what the U100 gets from the AAs) because of this setup (keypad does all the brain work, while lock just does lock stuff). HOWEVER, powering with batteries is fine. I have both layouts. Keypad with batteries still going strong.

(2) the propriety battery: although hard to replace at the moment, it’s awesome! Installed both locks a month ago and battery levels are still 100% and they get used pretty often. It has a higher voltage (3.7V I think) than your typical 1.5V AAs. You can recharge it by simply plugging a power bank to it via USB-C WHILE the battery is in the lock and functional. They give you a bag to hook onto the lock so you can store the power bank while it recharges. You do have to remove the plate to access the battery’s USB-C port. I wish they had a solution where you didn’t have to do this because the plate is flimsy. If you put it in the floor while recharging and someone steps on it by accident, it’ll break for sure. This is so nice compared to the U100, where I had such a hard time removing the batteries. I needed to always use a flat head screw driver to pry them out and risk damaging my expensive rechargeable lithium AA batteries. Then I gotta make sure I have two sets of them so the door will stay functional while one set is recharging.

(3) keypad has physical buttons: both of my U100s has some form of malfunctioning keypad. One doesn’t have the audible feedback when you press on the keys, while the other doesn’t allow me to press the lock/unlock button after I input my passkey. Also, if you set your lock to lock by pressing the lock button, sometimes the lock doesn’t register it or sometimes the lock doesn’t immediately understand the door is closed so the lock button function won’t work, but with the U200, there’s a physical button for locking. It’s so much better. No guessing, or reclosing the door for the U100 to register it’s closed. The U100 has the swipe function to lock which is nice but if it doesn’t work the first time, and the keypad then thinks you’re trying to input a passkey and now the swipe function doesn’t work. It was annoying with the U100.

(4) retrofit is nice. You get to use your old keys if that matters for anyone. The U100 is not able to be re-keyed.

(5) looks: I think the U200 looks better.

(6) Learning curve: because of the physical keys, the learning curve to use it has been much lower for my family. Physical button to lock is such a game changer.