Nope. Same machinery. Similar formulae. Price and country of origin (if you care) are the considerations after looks. Some people just like thick, but you could use plywood to raise 2cm and have a laminated edge to cover it.

I think they only real differences are in the colors/patterns. Caesarstone seems to have the most "white" choices, which was what I was looking for. But when it came down to it, we got a much better price on Zodiaq in a color that worked for us (Papyrus). It was difficult comparing prices, because some shops price based on square footage, installation included. Others sell you slabs then charge for the installation, edges, etc. Make sure you know what the charges are for finishing the sink hole, additional appliance and faucet cut-outs, etc., so you can compare apples to apples.

I was told that the 2cm requires a plywood underlay for support. You'll find that some shops won't install 2cm in a kitchen and will push you to buy the 3cm.

I don't think the colors are even very different. I have all the greens made by Zodiaq, Silestone, and Cambria on my table right now, and many are nearly identical. I'll probably make my choice based on my GC's recommendations regarding the respective installers.

2cm engineered quartz is siliconed on on the sides of the cabinets. At least it is in some places.

I had an installer at my place yesterday. First thing he said was "all you need are the sides." The counter rests on cabinet sides, on a bead of silicone.

I saw another kitchen done this way in 2009, in another city 500 miles away.

To install a quartz countertop, you silicone it onto the top of the cabinet side panels. The other panel, crossing horizontally, is not necessary except as a spacer -- and in fact it must be removed for an undermount sink to be installed.

Plywood is a bother, and if your counter is longer than the plywood, it's a big bother. If I wanted to raise my counter a little higher, I could cut a 1" bar of stainless steel into 24" lengths and screw them onto the tops of the numerous cabinet sides. Or I could cut strips of a discarded panel: it's OSB inside which is as good as any other material.

hth