As far as towing goes, the GX and the LS produce almost identical HP and TQ, he identical chassis less slightly different suspensions depending on GX trim, so it comes down to two things in re to towing, the transmission and power train mild hybrid vs straight NA. I've towed a friend's 7,000 pound trailer with my LS around town just to see what it felt like, slow and at speed, flat and up uphill, and I could tell it was there compared to a 4,000 pound trailer, but it didn't exactly struggle. Where I think one would really notice and where you'd want to watch would be up mountain passes when your hybrid battery is depleted, and you're running on the gasoline only, as well as descending where you might have that load really pushing forces back up through the tranny. All in all though I wouldn't be worried about towing at 6,000 pounds at all.