think about this...
I don't mean to burst everyone's bubble, but the reason the chrome gets hot is because it "absorbs" heat from the air! The rubber or plastic doesn't absorb heat as well, therefore it isn't as hot. Now, you need to figure out if the chrome (or any metal) is getting the heat from the air going through the intake tube (which would be good) or is it absorbing the heat from the engine bay (which would be bad)? You might think that the engine bay air is definately hotter than the intake air, but you would be surprised. The air going through the intake encounters lots of friction going through the box, filter, tubes, etc and no room for the heat to dissapate unless the tube absorbs it.
Now this all depends on setup. If you have the intake tube running over the radiator, then you definately want plastic so it doesn't absorb the heat from the rad and transfer it to your air into the engine. But, if your engine bay has good cooling then it may be a different story.
In my Nissan 240 SX, I was going to get the aftermarket metal intake tube, but it was designed to run right over the rad. Therefore the stock plastic one was better. However, in my friend's civic si, he had the metal tube because it was able to be installed right in a cold air path and to the front of his engine, mostly away from any heat.
I'm sure the rubber tube will work well in our case, but I think it should be tested first before everyone jumps on the bandwagon.