Generally the switch from 5th to goose is for simplicity and bed space when not hooked up to the trailer. 5th wheel hitches are heavy and cumbersome.
No first hand experience either way but have friends that’s switched their 5ths to goose and loved the switch and others that switched back to...
Those 42's are on an aluminum wheel and weighed in at 20 pounds heavier per wheel/tire than my 39's on an aluminum wheel.
Know what they say, you "Can't Lose on 42's"
I've not been watching the market that closely, but it seems like the market is in a weird place. Seems like things less than $10k and greater than $25k sell quick. Everything between those amounts is hit or miss.