The lightest slide in I have found are the Adventurer models under 8 feet but still weigh in at about 4,000 pounds without gear..Ad in 500 or so pounds and it is clearly over most all 3500 SRW payloads and alot of dually payloads.
People who have never hauled a truck camper or ridden with someone who has one are shocked by the sway in cornering.Even with the mods it isn't like driving around empty..The new basement truck campers are taller yet adding to the sway the height creates.
Lance only has the 850 in a non slide for a long bed because everyone wants the room the slide provides.Those of us that prefer the non slide and non basement truck campers for the mountains, where height can be your enemy,are in the minority because few people take there $40 campers in those kind of areas.
So I can clearly see why someone new to TC camping would freak out at the corner sway and cash out as soon as they could..I always suggest someone new to it atleast ride around or drive someone elses TC to see how it acts..