We do not consider plastic water bottles to be suitable for human consumption in the long term. Obviously if you are dying from thirst and someone offers you water in a plastic bottle, you will take it.

But sustained and prolonged use of plastic is unsafe in our opinion. This is worse as the temperature of the water goes up.

We find that we can taste the plastic in both cheap 'spring water' non re-useable bottles as well as plastic water bottles. This is also true of 'BPA Free' water bottles.
We believe that it does more than just taste bad or make you feel sick but that these chemicals are building up in your body and causing damage.

Aluminium is toxic for humans, so manufacturers often line these bottles with - you guessed it - plastic!

As we need so much water, it makes sense to us to make sure it is a pure as possible, without the contamination of made made chemicals & poisons. We should crave pure water...

This is true spiritually too:
"If the light you think you have is actually darkness, how deep that darkness is!" - Jesus

Glass comes in many shapes, colours and forms. Some is not suitable nor safe for drinking water.

* While not commonly known, low quality glass can leech chemicals into the water. You need to be sure the glass you are using is high quality and tested for these elements.

If using a Safe Bottles glass water bottle, the benefits are many.
Quality bottles (like Kuvings, BBBYO) won't leech poison into the water, they don't taint or flavour the water and they can be recycled after use.

There are some drawbacks which include: cost, chipping (can cut the mouth), breakages, heavy to carry, let light in (increases bacteria / algae growth) and the lid often has to be plastic to accomodate the thread.