A good thread for creeper feedback.
I admit to being in the 'old scrap of carpet or piece of cardboard' for much of my life.
I had an old wood name-brand creeper, don't recall the exact name, but the wood delaminated and instead of finding some plywood to replace it, I pitched it.
A few years ago, I was headed to an electrical/electronics supply house for some wire and molex nylon electrical connectors for a project. I was in a Miami industrial district, about to pull into the parking lot, and as I passed an independent Porsche repair shop, they were bringing out stuff to the curb. What was being put out for the scrappers, made me park. First dibs!
I had a worker who was bringing things to the curb help me to load a HFT media blasting cabinet, a HFT creeper, a 20 ton bottle jack, and that was it, for me. All the pieces worked, some replacement needed, like gloves for the media blaster. I replaced the glass and got a better gun and a new box of blasting media, and since it was a benchtop model, I built a floor roller frame for it using BORA casters and 2X4's. I also added a filter, and made a stainless steel fine screen to fit inside the cabinet, and to protect the glass from etching. It works great.
The HFT creeper was ok, but after using it awhile, the middle wheel part of the plastic platform cracked. I added a piece of metal sheet, and through-bolted the caster, no issues since, and the opposite caster area has not yet cracked. I'm over 200 lbs and the creeper has worked well for my bulk. No catching t-shirts or long hair, I keep my hair short these days.
I added some oil to the bottle jack, and it works OK now.