Our brand new Whirlpool WRS321SDHZ08 (21.4 cu ft side by side) has exactly the same problems. The coil has 12 turns and is 8.5 in diameter. I was told that the 5/16" tubing has 1/4" diameter. With an extra turn for the tubing leads to the coil, I get a capacity of 9.4 oz. The air temp next to the coil is 36°. Service tech and I agreed on water temp, never much below 60° and averaged 65° over several portions in a paper cup (which has little heat capacity). Before tech and I measured it, the water had not been used for 10 hours. Previous Whirlpool top-freezer with internal water dispenser did provide a first glass of really cold water but subsequent glasses were not as cold.

Same issue with a WRS321SDHZ08 Sde-By-Side Refrigerator. And like everyone else on this thread, my previous 30 yr. old Side by Side never had this as an issue. It always dispensed cool clear water. I'm very disappointed with Whirlpool's lack of ownership of this issue. The fact that I bought this unit less than a year ago and that people have been experiencing this issue for over 10 years speaks volumes to Whirlpool's lack of caring re: issues brought to their attention by consumers...Shame on you Whirlpool!!!