Questions on installing rigid vinyl flooring

My wife wants to get rid of the carpet in our living room and install some type of other flooring. Today at Costco we looked at Mohawk rigid plank vinyl flooring. This is the interlocking flooring with a pre-installed back padding at $37 a box and $2.10 a sqt ft.

Does anyone know if this is decent stuff or is it the basic bottom barrel cheap flooring?

Next, does this need to be installed on a perfectly level floor. I assume it is floating but do they typically put down a self-leveling compound or slurry? Our house has no basement and is just slab on grade. I have no idea what the condition of the slab under our carpet is.

I am pretty handy and remodeled and restored most of our last house. I have done tile, siding, roofing, plumbing, drywall, painting and a lot of other things but never this type of flooring. I am trying to decide if this is something I could tackle myself or if I need to hire a pro.

 

If the planks have a padded backing they are meant to be floating, as opposed to glued. If you have any variation in your subfloor you will end up with some areas that will truly float and drive you nuts every time you step on them.
Glued planks would solve that problem if the undulations aren't too bad but I have not seen anyone glue down padded backed planks - some bodgit DIYer will no doubt put me right on that one soon.

The only surefire way you know what you will need to do is to lift that carpet and check the state of the concrete. You should be able to get a fairly good idea with a long level on a short pile carpet but if you've got shag pile don't trust anyone who says it won't need prepping if they haven't looked underneath it first.

Edit: I noticed in Florida that corporate landlords and dodgy house sellers would specifically lay a heavier pile carpet if the concrete subfloor was bad.

Edit #2: In answer to your first question, yes, plank flooring that retails at $2.10/sq' is scraping the bottom of the barrel.