Simplicity has ceased to sell equipment. That leaves Ferris and a rebranded one as Stihl.
My two have been good. The cheaper one I bought originally was a homeowner branded version sold at the dealers. It did have a crossbar break at the mount. I had it repaired and it broke again. I took it to a welder and he fixed it up with reinforcing and hasn't broken since. Simplicity used very good drive motors in them that were higher quality. My two ZTR's have a ZT2800 trans in one and a ZT3400 in the other bigger one. Both use spin on filters and I change the oil in them regularly myself in December after the cutting seasons are over. Not a easy job as access to the vent hole is a PIA with linkage in the way. I do it anyway lol. Fresh oil in them is a good idea I've found as they are a lot smoother in operation when it's changed with fresh synthetic oil in there.