Not a direct answer for you, but I haven’t used one with my early D4 (basically a D3), and haven’t had any dramas. 
Where a trailer felt ‘heavy’ on the ball, some more intelligent loading fixed any floaty sensation.
That said, I’m not towing a block of flats, rather, a big enclosed trailer with percussion instruments, and ~2t camper trailers.
				
			 
			
		 
			
				
			
			
				2010 TDV6 3.0L Discovery 4 SE remapped to RRS output, Alaska White, GME XRS-330c, IIDTool BT, Dual Battery, Apple CarPlay, OEM Retrofitted: Cornering lights, Door card lights, Power + Heated Seats, Logic 7 audio
			
			
		 
	
Bookmarks