The Nexus 5X has been my daily driver for about a year now, and it has held up very well for me.
I bought this phone looking especially at the camera, and in that respect, it has not disappointed. I have quite a few beautiful shots, and all of the photos I've taken have turned out nicely. There is a small flaw which has to do with focusing on videos, however. Videos can turn out too dark or too light because of the flaw, but this could likely be fixed with an update.
When I bought the phone, it was very fast. Everything loaded within fractions of a second, and it was a very pleasing experience. Now, it has slowed down somewhat, although updates have helped greatly. Clearing the cache also helps, but is termporary and has become less necessary after the latest updates. Mostly, I cannot keep very many apps open and be able to quickly switch between them, likely a result of only 2GB of RAM.
The display panel is nice, and I've never noticed any flaws with it. That being said, it doesn't have as deep of blacks as some AMOLED panels I've seen, as it is an LCD panel.
The Nexus 5X was built somewhat cheaply, and you can tell. While it is not terrible, the plastic build can feel cheap at times compared to metal, but it absorbs shock very well, and I've dropped the phone without breaking it. The camera hump can be annoying, but I've gotten used to it, and my case makes it essentially non-existent. All of that being said, the phone is very light and relatively thin.
I can almost get through a whole day on one charge, but usually not quite. While I think the battery will be plenty for anyone who isn't on their phone too often, streaming video or using social media drains the battery very quickly. I usually charge up around 6 or 7 o'clock to make sure my phone doesn't die, but it doesn't take long to charge to a decent amount.
The Nexus 5X has been a very good phone for me. While there are other options which will suit you better, such as the Pixel, or the ZTE Axon 7 and Oneplus 3T, this phone was a good buy for me at the time. I wouldn't really recommend it anymore, unless you want one of the best phone cameras for very cheap, but there is something to be said for all bands of LTE and CDMA, especially here in North America.