Earlier quoted context omitted.
Nexus 5 was not a tank in my experience. On mine the plastic frame cracked between the power button and the volume control (I think a reasonably common problem with this phone, I've never had a frame crack on any other phone). After that one button gets stuck on, which makes phone cycle reboot - OK - I can workaround that. Then the microphone went bad: that is caused by the crack causing pressure on the micro-connect…
The soft plastic casing definitely cracks easily. On the other hand it does not fail catastrophically. I have dropped my Nexus 5 on the floor more times than I can count and while it has miniature cracks around the button/power connector it's nothing that prevents the phone from working.
So my two complete failures due to the crack were not "catastrophic" then?
The case cracking is common, and those two failures were common enough: most users would consider the phone uneconomic to fix, and not everyone has my tenacity or skill to waste time fixing their phone.
I also think it was that phone where the flash slowed enough to make it barely usable.
Back on topic.
The only Nexus I have had that hasn't had a problem was a Samsung Nexus 10 (still goes, but stuck on insecure Android 5.1).
The only Samsung phone I have had was the original Galaxy Nexus, which was still going when I gave it away last year. It's problems were: 1. screen burnin (OLED) and 2. Google didn't release Android 4.4 (due to TI dropping OMAP4 support?) even though 4.4 came out within 2 years. That phone cost more than an iPhone 4. My colleagues got iPhone 4 phones at the same time, and they got updates for twice as long and their phones remained useful for far longer.
So my experience with Samsung hardware has been good. I have always avoided buying Samsung because I hate their modified Android versions and lack of updates.