Personally I have not used it. Yes, it is designed for easier partial water changes. The downside is, it can impact the water temperature etc. during water change if the user use the tap water directly.
I think you can try to minimize the water temperature fluctuation by limit the amount of water changed. Lets say, instead of doing 20~30% partial water change, you can do 10% at a time.
On the other hand, I have used my canister filter for water changes. First, I take the outflow tube out of the fish tank and place it in a bucket. So the water gets sucked out of the fish tank into the bucket. Then I return the outflow tube back to the fish tank, and place the intake tube of the canister filter into the buckets of water I have prepared. Yeah, I let the water sit for at least 24 hours before using them to make sure the temperature is at least at the room temperature.
