Frankly? It sucks. I have tons of problems with performance of the device itself and especially the camera. Sometimes the device is nice and snappy, and sometimes it lags like crazy for no apparent reason. There are tons of threads on the Internet about it.
Here's one. Supposedly, Google just released an update with their normal monthly security updates (yes, Google actually started doing this for the Nexus devices) that goes a long way towards fixing the performance issues on the 5X, but I haven't received the OTA update notification yet.
If it doesn't fix the problems well enough, I'm going to sell it and look at something like the Samsung Galaxy S7 Edge, LG G5, HTC M10, or *gasp* iPhone 7.
About that last bit: I never thought it would happen, but I'm seriously considering switching to iPhone. I am just completely disappointed at the state of Android. I absolutely love the features and design of Android, but I am beyond tired of the poor performance and underwhelming reliability/stability. I've had a bunch of Android devices. Other than the first one I used, the HTC Incredible, I've had problems with all of them:
Google/Samsung Galaxy NexusWhen I first got the device, it was okay. But over time as Google updated Android, the performance got worse and worse. By the time I had it for two years, I couldn't wait to get a newer device. The interface and opening apps was
extremely sluggish by the end of the two years. I tried using a version of CyanogenMod, but it would just freeze the phone frequently so I had to go back to stock Android. The battery life was miserable by the end. I couldn't even make it through my 9-hour work shift without having to plug it in.
Google/Samsung Nexus 10This device was a problem from the start. The screen would display a weird, flickering, bright line on the screen briefly occasionally. It would randomly reboot constantly and updates to 4.2.1 and then 4.2.2 only reduced the frequency of that issue. It wasn't until 4.3 finally came out that the reboot problem was resolved. The device sold poorly and seemed to be quickly forgotten by Google. They did release updates to Android for the Nexus 10 until recently, but anything after 4.3 seemed to introduce new bugs that never got fixed. After 5.0, the WiFi performance has been atrocious and it can't seem to even keep the launcher in memory after opening a single app. It can't even seem to handle Firefox with a page open that has a lot of ads. It will close it out due to the memory pressure. I've loaded CyanogenMod 12.1 on it (equivalent to 5.0.1), and it's very sluggish and the battery is basically shot. Sometimes it will just power off at 50% battery. Sometimes after charging overnight it will say the battery is at 0% still. Sometimes it will charge to 100% but then never reduce from that until it suddenly powers off. The screen flickers randomly. Absolutely horrible experience overall.
I've thought about buying a Pixel C to replace my Nexus 10 since Google has a 25% discount on it now but I'm wondering what I'll be getting into, especially since I've seen reviews that say it has a real bad problem with touch input. Plus, as many say, the Android tablet experience isn't all that great. Google basically made the tablet and phone UI the same as of Lollipop and none of their own apps really do a good job of taking advantage of the large screen space. Since Android tablets don't really sell that well, other developers follow Google's lead and don't really support tablets all that well. I'm not sure it's worth bothering with.
Motorola Moto X (2013)At first, this device was great. Awesome battery life and performance, plus a great form factor and great, unique features. But over time, it became more flaky and more sluggish. Google made changes to Google Now Voice Search at one point (after they sold Motorola Mobility to Lenovo) and it broke Motorola's implementation of the "OK Google Now" always on voice search system and it took them months for them to fix it. The result while it was broken was that you would just get a force close when trying to use it. Apps would force close all the time. The UI became quite slow and opening apps seemed to take forever. After two years, I was ready to move on. It wasn't as bad as the Galaxy Nexus after two years, but it didn't age very gracefully either.
Google/LG Nexus 5XMy experience the first few days was good. It was a huge performance upgrade from my Moto X, even though its storage was encrypted. But I quickly started noticing problems after that. The camera was extremely slow to open. Sometimes, pushing the shutter button did nothing at all. Other times, I would see a thumbnail of a picture I tried to take appear in the little last picture box, but later I wouldn't find the photo in the Photos app or in any other gallery, as if the picture didn't actually save to the storage. Sometimes when taking a photo with HDR+, the "HDR+ Processing" notification would get stuck at 100% in the notification shade and there was literally no way to remove it other than reboot. Sometimes I'd unlock the phone and find that it doesn't respond to touch at all. I'd have to lock it again and unlock it for it to work. Other times, I would find that the phone appeared to be frozen, except it really wasn't. I would be able to press the on-screen soft keys and would feel haptic feedback and see the button "light up", but normally the button highlight quickly goes away but in this case it would just stay there. If I pushed anything else, nothing would happen but then about 30 seconds later the phone would start responding and perform all my taps in extremely quick succession, usually resulting in some unwanted thing happening. I basically have to reboot my phone every two or three days to get out from under the performance lags that always seem to appear at about that time.
I really want to like Android, I really do. But I'm so frustrated with the day-to-day experience. Then I mess with my girlfriend's iPhone 5S running iOS 9 and it runs like it's brand new. Nothing crashes. There are no slowdowns of any kind. It's very quick to respond to any touch input with zero lag. I'm not a fan of the one-button experience, the launcher, or the completely horrible notification system compared to Android, but there is something to be said for the overall experience when using an iPhone vs. even top-of-the-line Android phones. They just seem to get the finer details right whereas Google doesn't seem to want to be bothered. Even when the other OEMs try, they just have Google's Android under the hood to work with.