The first two are different brands names for quartz. Soapstone is not a brand name. it is the name of a material, just like "granite" or "butcher block." Don't know anything about soapstone but many on this forum will have advice for you.

My kitchen has quartz counters by Silestone and Daltile OneQuartz (another quartz brand) and I have been very happy. Extremely durable.

The difference is in fabricator/installer. Find a good one and you'll be fine.

Silestone, Caesarstone, and similar are what is known as "engineered stone". They consist of crushed up quartz and resin mixed together. They're mostly quartz (95% or so), but there is a small percentage of resin (5% or so) mixed in to hold it all together.

Soapstone is a type of stone that is quarried directly from the earth and is sold in slabs -- the same as granite, marble, etc. It can be relatively soft (compared to engineered stone & most granites), but it can be sanded to "fix" scratches -- one of the nice features of soapstone.

You probably saw and worked on it in the science labs at school.

Many people have soapstone and love it. You will find many threads on the Kitchens Forum about soapstone. In particular, look for posts by Florida_Joshua, he's a soapstone fabricator who used to post here frequently to help those with questions.

Both types of counters are good choices, it just depends on what you like.

(There are also many threads about engineered stone/quartz.)

Agree with FeatherBee, it depends on the fabricator/installer, just service.

If you are in NY.USA, you can consider Leadstone,is a quartz manufacturing company, provides quartz countertops with high quality and competitive price,

welcome to make an inquiry and wholesale quartz slabs, 10 years limited warranty.