I've got an alloy tray on a 300tdi 110, it's pretty harsh unloaded- but I'm happy with it, I need every spare kg when loaded to (past) gvm.
The rear doesn't move much when I'm running light, I've found I actually take different lines to wagons in the steep stuff because of this. After driving some hills for a while we were checking a mates 110 wagon's new shocks and they were damn hot front and back so we checked my rear std shocks and they were stone cold. Thought his new shocks might have been suss till we checked my fronts- they were stinking hot.
I don't have a/c , but single cabs with a/c are pretty cramped. Mines got a couple of rope boxes , which come in very handy due to the lack of room. I quite often have 3 people in the cab ( don't know if 3 would fit with a/c- be mighty squeezey) Newer single cabs are only 2 seat.
Alloy tray's (mines often loaded beyond gvm )ain't real strong like steel, but this allows flex whereas steel trays can cause issues with chassis mount points through lack of flex

Brett

110 300tdi