Hello! Good to see you again!
If the longies you had were early Duofold merino, they suck. Yes, they do. And I know this from personal experience (my own and S'Knot's) I'd suggest lightweight Ibex, Smartwool, or Joneswares.
Ibex: http://www.ibexwear.com/shop/product...woolies-bottom
Smartwool: http://www.rei.com/product/719536
Joneswares: http://www.joneswares.com/item/Women...Tights/310/c71 (these are actually fairly heavy, but I've got several 270g items and they are very very durable!)