Galaxy S4 unlocked rooted Xposed etc etc etc.............
I don't really think it gets much better than this. That being said, I'm considering the Note 4 and Nexus 6 when I'm ready to upgrade. Fuck a GS5/G3.
What's wrong you don't like quad-hd display?
For me, it's all about modability (it's a word, I swear). The S5 and G3 just don't have the same support base yet, though the G3 is getting there. The S4 has an insane support base. With the bootloader unlocked, I can use any rom or firmware from 4.2 to 5.0 when it's released. Typically, downgrading firmwares is either very difficult or impossible for most devices. With the S4 I can flash, root, and install recovery all on the fly without ever having to touch a computer.
The Note 4 has qHD. Pretty sure the Nexus 6 does, too. Your G3 is moot at best. Enjoy your locked BL, though.