Well, this discussion is pretty much split. I just wanted to get some views on the matter.
My point of view:
I think that would be a very obvious choice but I also think that the UU is very powerful already. The traits and the Jav Thrower fit each other just perfectly. When you have lots of barbarians early on, you can send a lot of Javs out to get them. I've had a Jav Thrower rush and it is scary what they can do with enslavement. When you get some free workers, you can put them in some desert city (with water near by) and you can build settlers with those workers so fast it'll make your head spin. So you make a few free workers, join them in some small city, taking advantage of the traits, you build some settlers, take all the free space you have early on, make your new cities as powerful as your capitol very early on, build more Jav Throwers, send them out, get a "few" more free workers, connect the cities and work the terrain around them, build all of the great wonders and either win a cultural, wonder, or a conquest or even more likely, domination victory very, very early on and you are all set. Simple as that. So basically, the Mayans will be a monster early on.
Now, ask yourself, how much will the 0 range bombardment help the Jav Thrower become more powerful? The answer is obvious: if the Jav Thrower can still enslave when defending, this 0 range bombardment will make you even more workers. So this advantage might seem really small to some, but if you add it to the Jav Thrower, it is monstrous. I'm pretty much split on the matter but I'm leaning to the "no change" vote but it is just too close. Only if the traits were just a little different then they are right now it would probably make it easier to decide.