I did my basement RecRoom (about 15 x 32') in these tiles about 12 years ago. After a toilet plumbing leek upstairs the Insurance clean-up crew came in and ripped them all out as there was water underneath them. (source of mould) As they found more and more water they proceeded to rip them all out to replace the carpet that was wet and found puddle in the lows spots. (3 stooges). (I have my cold cellar floor lined with the insurance garbaged units in my new house.)
I installed these to help warm up the floors in the basement room. They do nothing unless you have an exit for the cold air stored underneath the tiles.
Also, if you install these units without any through ventilation you will have a puddle under them guaranteed, as condensation forms and cannot get out on the cold, insulated from the warm room air concrete floor surface.
The units are convex shaped to allow the surface to float and must be put down without any rocking. They will not flatten out over time and will annoy you forever, if you don't! Spare pieces of cutoffs can be used if you rip off the plastic bottom instead of buying all the spacer pieces. Trouble is you, sometimes you won't have many cut-offs until the last rows. I am not sure you can stagger the joints due to the convex shape.
If flow through ventilation is provided they should stay dry underneath and you should get some nice warmer carpeted floors in your basement. Other than that they are a waste of money and a source of mould. Sensitive feet can feel the arch in them through the carpet.
-----------------
Any and all pointers are appreciated. The web if full of info but I prefer to hear from this group.