There have been a lot of good reviews of the Note 4, but one of the best and most comprehensive is an October 10th review by GSMArena. It's 10 pages in length and you can read the complete review here; however, for those who don't want to read the entire review here's the final paragraph:
"That's that then - the heir to the phablet throne is here and it looks like there's no stopping it from taking its rightful place. Samsung really needs a strong flagship lineup for the upcoming holiday season if it is to recover from the slight dip over the past few months and we can't think of a better device than the Galaxy Note 4 to rally the troops."