Drinking water in CUN hotel zone
 

I've read different things - what are people's experiences with drinking water in the hotel zone? Are most hotel's internal water filtered? I.E., drinks at bars / restaurants within, or is it YMMV hotel by hotel? Same thing with restaurants/bars in CUN itself?

While I can't speak for more than the 2 CUN hotels I've visited, your best bet to avoid distress while maintaining sanity is as follows (and is how I travel in most of the world):

(1) The hotel water is going to be fine for toothbrushing and showering.
(2) The restaurant ice, in limited quantities is unlikely to cause you harm. The more tequila in your drink, the less likely to cause you harm from the non-tequila portion of your beverage.
(3) The hydration water you drink, or any restaurant water you drink shall come from a sealed bottle.

Good tips, generally how I practice too! - I'm headed to Hyatt Ziva CUN with wife and baby so was curious about other's experiences to avoid "distress" as you say :)

The hotels in the Zona Hotelera use a water purification system. The I've used is mostly from chillers using that water or "Electropura" ice. That being said, going out of the zone I'd suggest bottled water.

Food in the hotels and major restaurants is clean. (Try Los Almendros for traditional foods of the Yucatán peninsula - the Mayan influence makes the foods distinctly different from other regions of Mexico, such as soap de lima (chicken lime soup), papadzules, fish tikin xic, etc.)

But if going elsewhere use bottled water, ask if ice is purified, make sure cooked food is fresh, make sure fruits and veggies are cooked or peeled and freshly so.

The U S Centers for Disease Control and Prevention list some basic food and water sanitation tips here.

Went there last year and had no problems. Used hotel water for tooth brushing, ice, and drank bottled water. At restaurants in the hotel zone, whenever i ordered water I was given bottled water. My wife and I ate fresh fruits and vegetables and neither of us had any issues. My theory is that the hotels and restaurants in CUN are not staying in business getting millions of American visitors sick. Go and have fun!

Im sure they are not, but it pays to use common sense and take reasonable precautions. Not every property may follow proper system maintenance, maintain plumbing integrity, etc. though the better brands are likely to be uniformly assiduous in doing so and avoiding negative reports to HQ and on the Internet review sites.

I say this as one who has both lived in Mexico, and visited throughout the country and the Americas for a number of decades, traveling from luxury to backpacker niches.