It funny you mentioned that because I was thinking the same thing today.
The problem I have with the any aluminum/steel joystick(that is completely) is that it tends to be too heavy. I got them at one time, only to quickly get rid of them. Not only did they have at least some wobble, but they also were incredibly too tall.
For me, a arcade stick should have a lighter feel, and the grip just feels right with plastic.
Now I do understand the tops are plastic, and having no experience with the light ups..they seem to be better, but it still feels a little "busy" for me.
So I guess I am not much help, but my experience does come from the aluminum alloy that SlikStik sells, and I am sure these are along the same lines.