Ok, the SD card and battery WERE a deal breaker for me, until I got the S6 Edge.
People don't like change and many times the problem is people simply don't like change, not that there is an actual problem.
Every new phone and upgrade, there are people that don't like it. While I'm not saying this phone is for everyone or every Note 4 users, sometimes the answer is not the changes are worse, but it is just different than what you are used to.
The no SD card and sealed battery are easy to adapt to. I have never had a phone without an SD card, way back since tiny Nokia phones. Adapting to saving things on the cloud rather than the card is much easier than many think. People do this all the time and have been doing this for a long time.
Instead of having my wallpapers and ringtones on a card and just switching out the card, they are on the cloud and I put the ones I want on my phone. It isn't worse, it is just different than what I have always done.
The battery was tested long before this phone came out and the phone has been shown to use the battery better. That is one of the big things with sealed batteries, they have been shown to last longer that those that are switched out. A local Samsung rep told me that a long time ago, seems it is true.
Also what I have seen is people that actually have the phone have been talking about how things are working well, and they are getting run over by people that don't have the phone or want it, talking about how bad it is.
Sure I would prefer an SD card, but have found the change is very adaptable. Sure I would like to change out my battery, which I have done maybe once or twice in many years, with every phone I have had. Instead of carrying a extra battery, I'll carry an external battery that is fast charging and will charge the phone quickly. Again, not worse, just different. Instead of carrying a battery, I carry something small I can very quickly recharge with if I need to. I can do that in 10 minutes while in the car, sitting in a meeting or sitting at my desk or anything else. It really isn't different than carrying a spare battery.
Some people will never change until all the high end phones have sealed batteries and no SD cards and that is where we are headed. Some don't want to get the phone, fine, but some need to realize that things aren't always as you think, especially if you haven't used it all all.