I haven't SR'd a shiny, myself. I tried but I just grew really impatient. I'm hoping to SR for a Moltres when I get that far on Leaf Green.
I have a decent amount of random encounters. I do understand how SR and random encounter shinies are more valuable than chained ones, since, of course, they're hard to get, but *shrugs* I still think chained shinies have value. It depends on the catcher; if they think they're valuable, and treat them like that *and not catch a bazillion of them on one chain*, then I guess they are. ^_^
Some people just chain to get a heap of the same shiny, which, I think, is worthless. Which I understand myself, because just that one time, I caught 6 shiny Shinxes, and they're just... not really worth much to me, which is sad... D:
Wow, you have some awesome shinies! All of my shinies *'cept my new chained Pupitar* are what you'd consider "common" in the wild. ^__^