I have a premium plus without massage seats, and I can confirm that front heated seats are ok at best. The front of the lower legs has good heat but the back of lower legs and lower back don’t have heat. The 2019 Jeep Grand Cherokee that this GX replaced had much hotter heated seats both in the legs and lower back area. My 2019 Subaru STI with Recaro racing seats also has significantly hotter, heated seats.
The steering wheel gets hot in the 10 and 2 positions but not the entire wheel like the Jeep.