I'm not sure what you mean by "best in class", but my father-in-law's ancient Z1 lasts two days on one charge. I saw this first-hand.
Personally I don't have any battery problems with mine. Lasts a full day with my use pattern.
Unless the 6s lasts two days on a charge, it's far from being "best in class".
First of all anecdote matters very little when you compare things like battery life which can be objectively measured. If you don't understand the term "best in class", try Googling it instead of putting it in quotations and make a snide remark.
I don't care about how long it lasts for you, your father, or me.
Look at the link I provided. The battery life test was conducted under at 200 nit in a controlled environment. This shows how long it will last compared to other phones doing the same activity.
The 6s plus and 6 plus offer some of the best battery life in its class. I don't understand why it has to last 2 days on a charge to be "best in class" and I would appreciate it to hear your rationale.
How long a phone lasts is largely dependent on how it's used. I am sure most smartphones can last 2 days if they are in standby.
"(2) she was amazed at how much better photos my Alpha took, as in, there was really no comparison (mind you, it needs reasonably good light and we certainly had it)"
The Alpha's sensor is similar to the Note 4's, which should be pretty good. But to suggest that it's a "lot better"? Haha Really?
She also looked at the photos on the screen which she perceived to be better, so not exactly an objective analysis.