You're best to mix distilled with antifreeze in a 50/50 ratio. The antifreeze increases the boiling point of water, which means you will have a more stable fluid to transfer heat at 180 deg F plus. You certainly don't want water to boil in a closed system as it will expand and may reduce efficiency as well as cause you to blow a hose.
Additionally, I believe the coolants have anti corossion additives whereas water alone does.
Water Wetter is often used because it reduces the surface tension of water (the property that makes it bead-up) thereby improving further water's superior heat transfer ability while also adding the necessary lubricants and corrosion inhibitors.
Lowering the cylinder head temperatures in a high compression race engine lowers the already-high fuel octane requirements. A Water Wetter/water mix has a slightly lower boiling point than a 50/50 glycol mix and alone provides no antifreeze protection. It can be used in combination with antifreeze.
You reduce operating temperatures when you increase the percentage of water in a water/anti-freeze mixture. Plain distilled water has twice the heat transfer (cooling) capability compared to glycol-based coolant mixes, but shouldn't be used alone (100%) as a coolant. It lacks corrosion inhibitors and water pump seal lubricating properties. So, even though water is the best choice for transferring heat, cooling systems are designed using 40/60 ethylene glycol because water alone freezes at 32°F.
Just a note on water wetter.
The corrosion resitance in WW breaks down over time, so if your going with 100% distilled water + water wetter you need to refill water wetter once a year or so to keep up with lubrication needs.