Hi droidntn !
I just came from a Rooted S4, and am LOVING my Note 4 (NOT Rooted)!!
Battery life is WAY better, and the WiFi and Cell connections are too. As a Tech, I'll tell you that Samsung has a lot more real estate in the Note 4 to play with for the Antennas, so it's kinda a given you'll get better reception on all wireless items.
I played with the Fingerprint lock for a bit, but quickly disabled it as I use the phone one handed a lot of times and it had a devil of a time recognizing my thumb, even after I did the "Improve recognition" thing.
{He Shouts} WATCH OUT FOR THAT SETTING THAT WILL WIPE YOUR PHONE IF TOO MANY MISSES!!
It's in there under the Fingerprint settings, but you have to scroll down to see it (Dumb move Samsung!).
Great idea if your phone is stolen, but if you're not watching and you play with the Fingerprint stuff and don't realize it's there... ZAP one nice blank phone!!
If, like me, you go through a full day or more to get your stuff transferred and setup the way you like it and then lose it all ... I can hear the screams from here. Glad I saw it, since it had a REALLY hard time unlocking. I would have hit 15 tries, but used the password 1st. WHEW!
As far as Note 4 or 5 ; The 4 is such a beastly good device I took the plunge. Glad I did. My Wife pointed out to me years ago when I was in the same situation you're in - "There's ALWAYS going to be a new Tech just over the horizon. Stop messing around and go for it!" I now wait two generations between phones, wait for the desired device to start down in price, then jump.
Another reason I jumped was the BestBuy had a sale for $199 with a 2 year contract with Verizon (I was T-Mobile on the S4). When we bought two Note 4's and they rang it up they were $99 each!! Yeah, you're locked for two years, but the same scene occurs if you finance the phone with Sprint or T-Mobile ...
Don't know if you're Rooted, but I used My Backup Pro ($5 in the Play Store) to WIRELESSLY transfer using the Migrate function Root -> Non Root. Worked flawlessly, the easiest transfer I've EVER had. I did have to re Sync my Swype keyboard (which was an adventure) and upgrade my Business Calendar Pro to version 2, but the new version allows settings & Template transfers which greatly simplified my most used App.
Personally, why wait? The guy at BestBuy says he doesn't see the sale going away since they want to clear stock, so I'd jump if I were you...! IMHO.
Best of Luck!
PuterPro