I have a couple of the old S3 2:1 mixing pumps, which are on their last legs. System Three doesn't sell these pumps anymore. They recommend using a sensitive scale (like a lab scale) and mixing by weight. I'm not enthused. Clearly this is workable, but I have habits and a setup based on pumps, and am not set up to dispense, in particular, small quantities by weight.
I'll go that route if I have to. What do you more recent adopters of S3 do? Is there another source of 2:1 pumps I could use? Do you do weighing and like it? Or what else?