One word, awesome. I don't use them on my car right now because, I am short money and I have other problems. But most expensive coilover kits use pillow mounts ath the strut towers, which is partly why those kits cost well over 1500$ Depending on what kit you are looking at, some pillow mounts have the ability to adjust your camber and caster at the shock tower, which in my opinion is the best way, and easiest to allign. The pillow mounts ar stronger than the stock shock mounts and bushings,a nd are usually made of alluminum and steel which are a lot stronger than the factory parts.
Some kits dont make use of camber caster adjustment of the pillow ball mounts some do. If you have the money go with the camber/ caster plates, which is the same thing as pillow ball mounts.
The only bad thing about these kits are the price, usually a good kit will run 200-400 per tower, and they tend to be noisier than the stock mounts. Other than that if you plan on racing, auto x I would highly recomend them. If you can afford them then the next best choice would be
You can see the poly-urethane bushings on the progress kit, that is the next best thing, along with a good camber kit like K-mac or ingalls.