The free version has a lot of things in it. I purchased the paid one to support it, but it didn't add much but a few animations that I use.
I was going to try cyanogenmod, but after reading some posts on sprint forums, they say they are working on addressing the data issue. But I don't know if they will. I'd rather stay official to upgrade. If they don't release something in a few months, I may get a nexus 5 or try the cyanogen once its more stable. Some posts people still say they have data issues I believe.
The main thing that makes me love my nexus is my other post I had about the zero lemon battery. I love this thing and it was only $40 and my phone lasts all day. I haven't been to fond of sprint lately so if I get a nexus 5, I will look at att or tmobile in my area. Sprint signals been soo horrible in my area during upgrades. They say it will get better as 4g is slowly going up around here in Ohio, but its nowhere near other carriers for speed and reliability.