Polish baby, polish!
Just kidding. I think the last time this topic popped up we had a good old fashioned blow out of opinions. I can say that I have polished my tunnel. I used mothers with one of their foam speed balls. It took me about 90 minutes to do the entire tunnel, including the running boards, which were a PITA because they are the cutout ones on the AC mountain sleds. I did most of the running boards by hand and also had to do some spots the speedrball did not reach.
It looks great for as long as you don't use the sled and then will start to get scuffed up a bit and re-oxidize when exposed to the elements. The nice thing is once you get it all polished up once, it is way easier to do again. I typically re-do mine at the start of every season.
So I'd say if you like the look, go for it. It is really not that much work, but also be careful not to get any on the plastic parts, as it can be a bit of a bugger to get off. I now mask off areas I do not want to get hit with the polish.
For those that do not want to trouble themselves, that's great too!
-John