PEX tubing: if they have any weaknesses?

Speaking of beautiful and comfortable house, in the first place, it implies the appearance, placement of the interior, attractive design, etc. In this discussion of peculiarities of the location and communication systems and the quality of heat, gas and water pipes are usually not included in this list. But this is the most important component of any home, comfortable accommodation, which occupies a special place in the preparation of documents such as house designs. Today the Canadian market a wide range of communication pipes of different manufacturers. In particular demand because of its chemical and mechanical properties of PEX used. What are they?