Urgent question - Opinion on installing PEX piping

[Andy K]

We have a rental property in the Inland Empire in So Cal and the tenant living there was getting very high water bills for the past few months. When they called the utility company last week, they were told there could be a possible leak in one of the pipes. I had a plumber go by yesterday to do a leak detection, and he found a slab leak under the bathtub in the bathroom. The plumber suggests re-routing the pipes from the main water supply of the home to the bathroom, instead of digging a hole in the concrete and fixing the part of the leaking pipe.

He gave me a quote of about $2500 to re-route most of the piping in the home, and said he will be using PEX piping. When I read up on the internet, there seem to be a number of lawsuits against PEX piping and some plumbers even refuse to use PEX piping because of their quality. I would like to ask folks here if they have used PEX piping before in any of their properties? How is the quality of PEX piping, and should it be used instead of copper piping? Or is copper piping the better choice? I need to make a quick decision on this, since I need to get this leak fixed soon. Hence any advice is appreciated.

Also, does $2500 quote for re-routing the pipes seem like a fair price?

I found the above plumber reading good reviews on Yelp. If anyone on the board can recommend a good and honest plumber who they have used before and does work in Riverside county (So Cal), that reference will be much appreciated. Thanks for your help.