I picked up an S5 on Friday and I'm back to my Note 3. This is my 2nd Note 3. I sold m first one a while ago and regretted it ever since. Anyway, I tried the S5 for the weekend, went back to the Note 3 Sunday night. Tried the S5 again yesterday, this time putting the Note 3 in a drawer so it was out of my site. Ended up switching back to the Note 3 today.
I really like the size and feel of the S5, and the flatter look of TouchWiz appeals to me. But it stutters somewhat and that drives me nuts in a phone. So i'm probably 80/20 right now, with the 80% on the side of the Note 3.
I guess they are just too much alike, and the Note 3 adds features you just can't get on the S5, so I'm sticking with the Note 3.