Okay, been there done that...
Had wall-to-wall replaced in our house.
First, do not go to Lowes!!!!
Here is the lowdown -
PADDING - The padding is MORE important than you think. the cheap stuff can just disintegrate. The cheap stuff will not be good for the life of your new carpet.
Our old carpeting was a medium so-so quality installed by the contractor who built our home. We had it for over a dozen years!!! Better than anyone would have thought. When they took up this old carpet, the padding underneath was still in fair shape too.
Our new carpeting, installed from Lowe's, I can already tell is of a lower quality-durability... It still looks great, of course, but we can already tell that the padding underneath is way less than when it started out, after a couple years.
CRUSHING - I have heard that the true measure of a carpets quality and durability is the crush resistant factor. I believe that most carpets will have a 'crush rating' (under different names, of course) Of course, you cannot really compare the crush rating of a carpet by one manufacturer with the different rating scale of another. But, this along with the padding mentioned above, are two of the most important things to look for. Look for the number of years supposedly guaranteed against crushing and matting.
In our new carpet, the 'crush factor' is not nearly as good as the old.... How you can tell???? When I move furniture, such as dining room chairs, there are semi-permanent marks (crush holes), where this was never a problem with our older carpet. The spot where my son's chair is, which he uses all the time, sits there for home-schooling, etc... is definately permanently 'crushed'. You know, if this is something that you want to be concerned about - bring home the samples, and set something on them for a day or two.... Then remove the heavy items, and see which holds up, and rejuvenates the best.
TWIST - Our old carpet had more of a 'twist'... This is the amount of permanent 'twist' to the actual yarns/fibers. This, in addition to a slightly higher quality of fiber, meant that crushing was not a big problem in our old carpeting, even though it was only a medium so-so price and grade of carpet.
STAINS - You can look for something like 'StainMaster'. And from reputable maker, that might actually be a plus. But, take most claims for stain resistance with a grain of salt. Your carpet can also be treated with the ScotchGuard spray for carpets - available at many places.
FIBERS - Polyester is the cheapest, and, if I am remembering correctly, it can also sometimes be the more stain resistant. (think of how clothing with polyester releases and cleans stains better than many other fabrics/fibers) Nylon is considered to be 'softer' and has many other claims to fame. However, I decided that having 'nylon' was not the make or break factor for me. You might also want to ask a trusted person at your reputable carpet dealer about 'fading' with the nylons. I could be remembering wrong, but especially in my home where the morning sun streams in my big sliding door, bay windows, etc... I am thinking that polyester is more resistant to fading.
WEIGHT - Yes, to me, I wanted, and chose, a carpet with a slightly heaver weight. But, technically, weight is not everything... While you do not want a cheap 'light-weight' carpet... you do not necessarily want to think you should choose a truly super-dense heavy-weight carpet.
Bottom line, after having been there done that - I had narrowed our carpet down to two choices... one from Lowe's and one from a local carpet dealership. I chose Lowe's. I wished I hadn't. While I, personally, like the fact that I chose the more heavy-weight carpet... The other carpet was probably the far better choice as far as durability, crushing, etc... And, Lowe's installed what I now consider to be inferior padding.... The dealership was offering, for a bit more in price, the complete top of the line padding... looked more like a rubber utility doormat, with a smooth dark finish, not the kind made out of chunks of foam.
Also, that carpet was probably the better carpet, even though it wasn't as heavy/dense - I can't remember the maker, but it is the one where the carpet has an additional fabric backing.
I do have the info on the carpet that I chose... (which may NOT have been the best after all)
Maker - MOWHAWK
Name - Artloom (from Lowe's)
Fiber - P.E.T Polyester
Stain - Scotchguard Stain Protector and Stain Release
Density - 4680 (65 oz. weight)
Hope this helps!
Twist - 5.0 - 4.8
PS: No home with carpeting, and especially one with pets, should be without a good carpet cleaner.
After having rented them in the past, we went to Nautavac website and purchased a refurbished unit.
I don't know what I ever did without it!!!!!