Victor got dragged into this by me Ruck'n. As you can see it was very late when I posted, and my brain registered "Victor" when I saw the handle "smokinreefer" when I know dang well that it's Shao that holds the intellectual property rights to that handle. :?
Oh well, I'm sure that Victor was dying to participate in a new thread, so I just pre-empted his arrival. Think of it as a special lead-in just for him!
And to answer your questions, no I have never tested TDS at the different stages, but why would you? I don't suspect that TDS reading would change much (if at all) after the sediment or the carbon filters as neither would reduce metals much (which affect TDS readings the most).
And I have a built in pressure meter (just like in Shao's pic) so I am not able to test pressure at each stage.