I did my whole house in a couple days with PEX and have been very happy with the results. Didn’t have a single leak in any connection.
The first thing is what connection method will you use, and then getting the proper tool to do the connections. I like the stainless steel rings that crimp on. One tool does all sizes. You will need a crimping tool and a tube cutter.
I started at the meter and went to a T with .75”. One side to water heater and on to a hot manifold the other to a cold manifold. I will add a photo. They sell ready made manifolds but I made my own using two copper manifolds and a bunch of ball valves. I ran .5” to everything on the first floor thru the basement and up thru the floor, as what they call a homerun. Each thing has its own line from the manifold. To the second floor I didn’t want a bunch of lines so I ran .75” up thru a wall and branched out in the bathroom using .5”.
I ran all white, but they do make red and blue for hot and cold. I just put a wrap of red tape near the ends of the hot runs and didn’t have to buy rolls of each that way.
Run it almost like wires and they sell nail on clamps to hold it. They make every kind of fitting you can think of with the barb end for the PEX. They also sell Shark Bite fittings that just slip together. They are expensive so I used them sparingly where I wanted to easily remove a line some day. Like at the water heater. Shark Bite fittings can be used to go between your copper and PEX also.
It is hard to make a sharp bend 90 without kinking the PEX. They have a piece that allows you to turn a corner and hold the PEX. Shown in photo. Doing the homerun method and using these pieces for corners I don’t have any connectors hidden to worry about.
If you do the job ask as you go with any questions.
The only negative I have heard about it is some people say rodents like to chew it. we get a mouse from time to time but I haven’t seen them go after the PEX.