This page compares the seats in the F-84G 48th scale Tamiya kit, the Cutting Edge resin detail set, and the Aires mixed media detail set. In each photo, left to right are Tamiya kit seat, Cutting Edge resin seat, and Aires resin seat.
The Tamiya kit seat is basic and devoid of much detail. The foot stirups for the pilot are a separate part, and are not correctly shaped. None of the other details present on the real seats are molded into the seat, and the harness consists of a decal. The Cutting Edge seat is very detailed, and includes all the details of the real seat, including molded-in foot stirups and harness. On the suface, this appears to be the best of the three seats. However, it is too tall and does not fit into the cockpit as it should. The Aires seat is also very detailed at about the same level of detail as the Cutting Edge seat. However, the harness is supplied as photo etched parts, and the arm rests are separate parts that have to be glued to the arm rest supports.
The back of the Tamiya seat, like the front, is devoid of any real details. The ejection seat rails are a separate part, and must be glued to the back of the seat. The back of the Cutting Edge seat has more detail, and the ejection seat rails are molded as part of the cockpit with their set. The back of the Aires seat has the ejection seat rails molded-in as part of their seat.
Side view of the seats shows no details on the Tamiya, moderate details on the Cutting Edge, including some of the ejection mechanism levers, and the Aires shows a great amount of detail. Note that both sides of the Aires are shown, as I bought two of these sets. One of the seats has the front arm rest mounts missing; they were not in the package, so were missing when the parts were packed -- poor quality control. Note also the difference in height of the three seats. The Tamiya is .525 high, the Cutting Edge is .635 high, and the Aires is .575 high, measured at the base of the back to the top of the back. The measurements do not take into account the thickness of the foot stirups or height of the headrest brace. Based on the drawing of the seat from Republic's manual, it appears to me the kit seat is the correct proportion for height to length. Actually, the other two are also at about the correct proportion, the big difference being the thickness of the seat bottom (top of seat cushion to bottom of seat back) which is where most of the difference in measurment lies. The Aires seat does fit when the base of the casting is cut off, but the Cutting Edge seat does not clear the canopy without removing extra from the bottom of the seat. Also, the slope of the Cutting Edge seat back does not match the slope of the ejection seat rails molded into their cockpit tub.
After comparing the seats, I conclude that the Aires seat is the best to use for replacing the Tamiya kit seat. The Cutting Edge seat may have a bit more visible detail -- after all, it is unlikely any of the side detail on the Aires will be visible when the seat is installed -- and the molded-in harness is a joy to behold when detailed properly (I've seen a completed kit with the Cutting Edge detail set installed). However, the Aires seat fits better as supplied and the photo etched harness can be detailed nearly as well as the harness in the Cutting Edge set.