Hi, I am a mechanical engineer and I have designed double wishbone independent front suspension in OEM vehicles. The MacPherson strut is the other common street-car suspension design. To understand and evaluate suspension design you have to understand the dynamic forces and kinematic motions of the linkages. The OP obviously does not have experience in this area which is crucial if you are going to judge something as complex as vehicle suspension members. In general, the lower control arm (LCA) carries a lot of the forces (suspension, turning and braking forces) and is meant to be the main structural linkage. The upper control arm (UCA) is moreso used as a follower-linkage that doesnt have to support as much force as the LCA, hence why it is always much less "beefy" than the LCA. Because of linkage design, you can't simply compare one trucks UCA with another as the total linkage design is different between the two. I noticed that the CT spindle is very tall, this separates the distance between the UCA & LCA ball joints. Because this distance is much more spaced apart than on typical pickup trucks, it allows the UCA to be designed to support less forces. Engineers use extensive FEA models to understand the stress/strains that the component is subject to based on the weight of the vehicle and the geometry of the suspension. Then it is subjected to lab testing, manufacturing testing and real-world testing. Pretty idiotic for a troll online to look at it without any experience and say it is bad...although that is the world we live in these days.
The main downside that I saw about the spindle design is that it leaves no clearance for larger tires, or even tire chains without rubbing on the upper spindle ball joint hardware. Most truck owners like to put larger tires on, but I dont see that being an easy option on the CT. (Not that I personally think it needs larger tires)
