Had my 6s Plus for a couple of weeks now and man am I happy w/ the purchase. I came from a 5 that I've used for the past 3 yearsish (broken home button last year and a half) and the difference is night a day.
It's obviously so much faster, but the two biggest differences for me are the screen real estate and the battery. I didn't notice at first how much bigger the screen was w/ regular use, but when I had to use my wife's 5s for something, it was like picking up a toy, I couldn't believe how tiny the thing felt in my hands. There are still times were the size of the Plus is a little annoying, but 90% of the time I'm completely comfortable using it and the 10% of the time where I have to adjust my hand awkwardly or use 2 hands to do something is well worth the increased screen size.
Now the battery, good lord this battery is my favorite thing about the phone.
I have a battery longevity question: As of right now I commute roughly 2 hours a day, during that time I have my phone plugged into my car audio. Now the input I have it in charges very slowly, but the way it's been working is I wake up in the morning w/ a 60%ish charge (don't charge it overnight) and after my hour commute in the morning, my phone is in the 75-80% range. I make it through the day and get back into the car on the commute home again in the 60% range, and by the time I get home I'm back up to the 75-80% range. So really the only charging I do are these 2 hours of commuting, and as a result, my phone is basically never under 60% (and not usually above 80-90%). Is this going to hurt the battery long term? I don't really have a solution since the only way I can do podcasts/music from my phone in the car is through this lightning connector port. I'll probably get a new phone w/in 2 years so if this is only going to slowly erode the battery more than if I just plugged it in to charge once a night, then whatever, but if it's doing serious damage to the near future of my battery capacity, then I'll suck on no podcasts I guess. (Also, even w/ the 2 hours of it being plugged in during my commute, am I better off topping the phone off overnight so that I start each morning w/ a 100% charge? Theoretically for the morning commute at least, the phone wouldn't really be 'charging' as it'd just be staying around 100%)
My very limited understanding of rechargeable batteries is they have a certain number of charges before you start getting diminishing returns, and I don't know if having it plugged in twice a day, an hour each time is eating up those theoretical charges.