Which of these two truck campers should I buy and why??

Seems high priced for the Lance. Our Arctic Fox was less than your quoted price and the Lance was even cheaper than ours last year. We narrowed it down to Adventurer and Arctic Fox when comparing build quality and capacities. If we didn't want a slide out, the Northern Lite would have also been a top contender due to its fit and finish even though the capacities were less.