Indeed... everything you posted is the exact opposite of my experience with stock Nexus 5 and my non-techie friends with their S5's and Galaxy Notes.
Also, I easily get about 24+ hours of battery life on my Nexus 5 with 4-5 hours of screen use. If you look on the Nexus 5 subreddit, some people have difficult getting more than 3-4 hours of screen time while others (like me) have no problem getting 4-5 hours.
The iPhone/iOS just seems to have a better-optimized LTE stack. If you look at Anand's data, the iPhone drops less than 5% from WiFi to LTE, while the Nexus 5 drops 23%. iOS seems to also be much more aggressive about powering down the radio to avoid burning a bunch of battery life in bad signal conditions.