I have two neighbors who got a quartz countertop from CTM. I saw both installs and they were very good. In one install they dented the wall when they pushed the countertop against the wall so it had to be fixed.
I got a quote from them too, and I tried to get a better price elsewhere because I wanted a cash deal. I ended up paying the same as the quote I got from CTM, but I got a worse quality sink and whole range of problems including dent in countertop, dent in my cabinet, showing up without calling, problems getting it without a join/two pieces, etc. etc.... CTM asked my neighbors if they want join or not but they didn't ask me unfortunately, if they had I may have gone with them, because without a join the price is a lot cheaper and the other company was easily able to lure me with the better price.