The point someone made about going to the store is more than about "feeling" them. There are plenty of phones out there with "fast" CPUs but the software on it slows them down. Any of the options you listed will be better than your current device. Playing with the phones also give you a chance to check out weight and that sorta stuff too.
With that said, I use a Nexus 5 and still loving it but the Z or the G2 is what i'd say from your list.
There are newer devices out there but does you no good if you don't like any of them.