The Nexus 7's storage degraded, which rendered the device unusably slow. I thought it was the upgrade to the next version of Android that did it, but downgrading it did not fix the issue. There's been some workarounds that made it slightly more usable but ultimately it was a serious hardware defect that made it unbearably slow to use even with these workarounds.
The Nexus 5 had a bootlooping issue — I had the issue occur on my first Nexus 5, 2 weeks out of warranty. Fortunately Google was kind enough to send me a refurbished one... that shortly after had the same bootloop issue.
My opinion of Google has gradually deteriorated over time to the point now where I actively avoid using anything made by Google because 1) they can't do hardware right and 2) they sunset way too many products for me to feel comfortable using them. So the promise of 7 years of OS updates on a hardware device by Google just seems empty and maybe pointless because I don't trust the device itself will continue functioning, even if the updates keep coming... which I have doubts they will.
While I was still using Android, my Samsung Galaxy S6 was probably the most headache-free experience I had, even with the complete lack of feature/OS updates but as it stands, my iPhones have all been rock solid devices, so that is probably what I will continue using unless something drastic changes.