I went from a Galaxy S3 to a Note4 recently. Pretty similar phone for sure, but the battery life on the Note4 is AMAZING. I can go pretty much 2 entire days of use with no recharge. But seriously most noticeable thing for me was changing providers. I am not sure if it is just where I live but I had Sprint with the S3 (and several older phones) and there service was simply terrible. I switched to Verizon and it is night and day. No waiting on anything, completely full data and phone service everywhere even places you wouldn't expect to be able to make calls. That being said the service does cost a pretty good deal more than Sprint for the same options.
?EDIT- Also I ordered the Note4 off a website without ever handling it based on the listed specs for it. Had I known it was so huge I would have chosen something else. It is almost impossible to use 1 handed and it falls out of hip pockets and gets in the way of anything involving movement. You pretty much need to wear cargo pockets to carry it around. But performance wise it is def good.
