3.5 ton for one side of the house, 5 ton on the other side.
5 ton unit had frequent plenum leaks. As in there seemed to be so much back pressure the tape seals and mastic would be blown out and leaking air into the garage.
Property owner was quick to have AC techs out, but failed to actually fix it properly. This went on for a full year. Upstairs bedroom never cooled or warmed up depending on temp. My thoughts are the people that installed this did it half assed.
5 Ton unit had one 16 insulated flex duct trunk line running between floor joists 12" on center and maybe 16 inches long. Two returns a 16 and a 12 inch.
At one point the unit had the inspection plate on the side literally ripped the sheet metal screws out. AC tech came out, apologized and explained that he told the owner what needed to be done. Then put in some new screws and left.
We've moved out of that place, but wanted to hear from some other people with more experience. Home is in Florida, Tampa Bay area on the water.