if you switch to xt (rapidfire) shifters, wouldn't you also have to change to a regular xt rear derailler (from your xtr rapid-rise)?
at that point, i think the weight savings would be a wash. and you'd be out a bunch of money, even if you get stuff at a good price.
i compared an xtr shifter/brake/rear derailleur setup, with a set of marta sl's, sram x0 triggers and rear derailleur. the sram/marta setup was lighter. i don't remember exactly how much, but it was less than 100grams difference.
at that point, i think the weight savings would be a wash. and you'd be out a bunch of money, even if you get stuff at a good price.
i compared an xtr shifter/brake/rear derailleur setup, with a set of marta sl's, sram x0 triggers and rear derailleur. the sram/marta setup was lighter. i don't remember exactly how much, but it was less than 100grams difference.