Leathers being equal, is there any appreciable weight difference between a 35cm Kelly and a 35cm Birkin? I know many people find the 35 Birkin to be heavy after a few hours, but I've never heard anyone complain about the weight of the Kelly except for 40 cm. I'm considering a box leather 35 Birkin and am wondering if it's going to be much heavier, if any, than my 35 box Kelly (which I find a teeny bit heavy). Opinions from those of you with practical experience would be greatly appreciated.