First is your phone rooted?
If so you could install a script such as crossbreeder (which I use myself, it's on xda developers website) I'm not 100% sure that it will run on your version of the device since from what I know the one v outside of the U.S. is a gsm phone.
But if it works it will adjust the memory settings to get rid of most of your lag issues. Has a built in adblocker, a governor tweaker, and Io tweaker, among other things.
Also I'd recommend getting "cache cleaner ng" which will automatically clear your caches at a time you decide and allows you to specify what apps you want cleaned. I have mine set to clear the caches every 12 hours at 3 am and 3 pm.
I also partitioned my sd card (class 10, 32gb card), and moved most of my apps and caches to the sd card. By using "mounts2sd" I've been able to get my internal data down to 39.03 mb out of 960.64 mb on the phone itself which has made a world of difference.
I know myself that I was suffering from some serious buyers remorse after about a week of having the phone, by doing the above and installing a custom rom running 4.2.2 I was able to get rid of most of the lag.
my specifics;
rom: rythmic rom 1.4
kernel: one that came with the rom
clock settings: 368 - 1804/ondemand
IO settings: SIO
memory management settings: allow purging of assets, enabled ksm, zram set to 26%
enabled 16bit transparency
Hope this helps