alphaemo
It depends on your needs and what's right for you.
I too was debating between the two but stuck with the EVO LTE for my needs. The speaker is clear. The screen has sharpness to it. It's a lot lighter and thinner than I expected. It has a external sdcard slot (unlike One X). Battery life is really good and larger than the One X.
If you are not leaning more on either choice, I suggest you wait and play with the phones. You can't go wrong with either choice.
In case you didn't know, Samsung Galaxy S 3 has a dual core snapdragon and 2 GB of RAM compared to International versoin (which has quad core and 1 GB of RAM).