Dane wrote:At least one reason - Some people prefer you not use aluminum descenders on their rope. At least in TAG, it is pretty common to share rope.
Change to SS - You lose some friction, but you make more friends!
We(club) use Aluminium racks on our ropes after washing you wouldn't know the difference.
Dane wrote:There are also those that feel that the increased friction comes at the price of increased heat, perhaps to the point of glazing the rope.
If you go down the same rope at the same speed on either device the amount of fricton you 'use' is the same whether the bars are Aluminium or steel (your hand might get warmer though).
Aluminium tends to transfer heat better than stainless so it may feel hotter but that's only because it's better at getting that heat away from the rope (which is a good thing)(Computer CPUs generally use aluminium heatsinks).
PS: I prefer my stainless steel rack to an aluminium one, but that's because it is faster and on small drops with stiff ropes I won't have trouble descending with a stainless steel rack, (feeding rope into a rack is a dangerous practice, better to pull it out the top)