I cant speak to IOS, but usually the jumps from one google OS to another tends to be pretty significant.
Lollipop acts/looks NOTHING like Ice Cream, Jellybean, or Kit@kat...and most of the time, they tend to improve on battery life too, or at least thats the goal until it gets released to the masses then they find other issues.
@cinco, the Oneplus One is legit. My only problem with them was the invite system to purchase one. Chemix was on point. The specs and the price point are an absolute steal for a phone like that in this phone climate. When i FINALLY got an invite to buy one, i ended up passing on it b/c i wanted to see what they would do when they announced the oneplus Two and that phone at one point used Cyanogen mod as the OS, but now they have their own OS which i've read is actually pretty good as well.
But i was team Samsung until they started basically doing the same stuff they used to troll Apple for doing. Im up for a new phone now, but im just sitting back waiting until something i like comes along.