The Bright switch, which only affects the clean channel, is voiced very musically, adding a subtle shimmer with no piercing ice pickiness. Another way I set the amp up was to set the Drive control at 2 or 3 for a barely dirty clean tone, then hit More Drive for my crunch tone, then use the Normal channel with a distortion box (set for a massive boost) for my lead tone.
Blackett, Matt (2014) Fender Hot Rod Deluxe III. In: Guitar Player, Vol. 48, No. 10, pp. 110. Available at https://openmusiclibrary.org/article/765313/.