And with copper there are pinhole leaks, copper toxicity and busted pipes due to freezing.

Just saying that there are issues with everything AND some of those issues are significantly overblown unless you have a specific situation.

So, do you have a rodent issue? Do you have plumbing that could be exposed to freezing? Do you have acidic water? Will any of the pipes be buried? Is this a house that will be unoccupied for long periods of time?

Note that the "chemical leaching" issue is significantly overblown. PEX has been used in Europe for decades and has been used in the US for about 40 years or so. The only known issue - and this is out of an abundance of caution - is that California says that the lines need to be thoroughly flushed after finish plumbing is installed. The reasoning is that:

1. The tubing is brand new at construction and is the time when it would most likely have chemical residue.

2. Water sits in the pipes starting at rough-in during a pressure test

3. The water sits in the pipes for weeks or months during construction

4. If the lines aren't flushed at plumbing finish then workers can be exposed to water that has the highest potential to have leached chemicals if they drink the water.

5. It would be the same workers (think trim, paint, drywallers) that would have this potential elevated exposure over many jobs because they come onsite at the same point in construction.

That's a pretty specific set of circumstances that's not likely to be repeated by the average home owner.

I used Pex-B in my house because it's cheaper and more common than PEX-A, has a higher bursting strength, and because it has lower residual/leaching potential than PEX-A. I've had no taste issues at all.

I remind folks that all of the plumbing is certified and the pipes in the house are the last 100' of plumbing that in most cases has traveled miles in God only knows what (not to mention the groundwater, streams, etc).