I have the GM hatch mat and weathertech in the front. The GM mat is great for the price fits well but the lip is small but more than sufficient for my needs. I only use the weathertech in the “muddy snowy” season.
Funny, I have the opposite, weathertech for the hatch, GM for the footrests. As for which one is better, it’s hard for any of us to say, we don’t exactly go out and buy all of the money and and comparison test them. So all of us would naturally say what we bought is better as we phychologically don’t want to think we made a purchase mistake. The only time someone would gripe is if the product has poor quality or failed us.
As for price, you paid much more for the car than the floor mats, get whatever you want and don’t let $10-20 sway your decision - cheapest isn’t always better, though cheapest and best quality should always win out. Sometimes it’s just the ability to select color that wins. And since you posted in a gen1 forum, you might discover that they’ve stopped making your particular year (I wanted weathertech floormats for a 2004 CTS and they are nowhere to be found - I thought they custom made them and should have the computer based pattern somewhere, but no).
One thing I did not expect, after adding the cargo mat, it’s harder to get under the floor to pull out or put away the EVSE. So my EVSE ends up sitting in the cargo area taking up space unless I absolutely need the space, then I’ll put it away. Not having a cargo liner would have been one less impediment (though having to wind it up to store it would have also stopped me many times)
BTW, have you added a voltshelf and voltscreen yet?