I am now about to be on my third soap dispenser to match my faucet.  The plastic cartridge inside sticks after you push down for soap instead of popping back up.  At first, it was just a nuisance, but it gradually gets worse until the device is entirely unusable.  Unlike some other brands where you can take an assembly apart to get to a busted spring, this one does not appear to be user-serviceable.  I can't believe that Delta doesn't sell a replacement part for the little cartridge.  Shame on me for not saving receipts - I mistakenly assumed it was just that my first one was a dud, but it appears to be a design flaw.  It is looking like it will be more economical for me over the life of my kitchen to replace my entire faucet with another brand rather than continue to replace these.