We have found that we get faster results if we adjust the flow through the chiller based on the amount of heat picked up. If we run at full flow, either with tap water or the ice water recirculation, we didn't pick up as much heat as we did if we slowed it a bit. Not much, but it was obvious we were getting more heat at the discharge.
I hate to beat a dead horse here, but faster is better when it comes to flowrate.
You will feel hotter discharge water with slower water, yes, but that doesn't mean more heat is being removed.
Think of the water like trains, and the heat energy like people. Say you have a whole crap ton of train stops, with a whole crap ton of people.
If you have just a few trains per day, each train (water), will carry more people (heat), but there will be a longer delay in getting all your people from point A to point B (A being the kettle, B being your driveway/sink).
If you have TONS of trains per day, you will only have one or two people per train, (not much heat in the water), BUT no person will have to wait long for a train to come, (so in the end, people get moved faster).
The key here is the difference between HEAT and TEMPERATURE. Your slower water is higher in temperature, but contains less heat flow. For a clear difference between heat and temperature, look at a bathtub and a needle. Heat the needle to red hot, (hundreds of degrees). That needle has a lot of TEMPERATURE, but no HEAT. No heat, because you stick that needle in a room, and the room won't get appreciably warmer. Now take a bathtub of water, and heat it up to only 100 degrees, (hot tub water). The tub has tons of HEAT, even though it doesn't have a very high TEMPERATURE. Lots of heat, because the room will get warmer as the tub cools.