I have a burley Bee double. It's great. It folds down quickly and fits in the trunk of our car. This has worked well on vacations where we took bikes and threw the toddler in the trailer (once unfolded and out of the trunk, of course). It's super convenient for the small footprint and rides well (obviously offroad capacity is limited), and you barely notice the extra weight except on climbs. It's currently on loan to a friend who has a toddler.
I also had a bob ibex. It was great too, but probably more heavy duty than necessary for me. I also felt the weight more with 1 wheel in the back, parking was a bit of a chore, etc.
I also have a clydesdale setup on an old mb-1. It's unwieldy with heavy loads. Yet, it ends op being the bike I ride most around town. It takes the planning out of a trip. Sure, I can stop by the Portuguese shop and pick up a rotisserie chicken and fries on the way home. Need me to bring a case of beer and a bag of chips? Are we going swimming and need towels and water wings? We need a frisbee and a soccer ball? I appreciate having a huge wald basket just to toss in whatever you need without thinking about panniers, etc.
If you want dedicated hauling and N+1, you can't beat a dedicated cargo bike. If you want to occasionally use your bike (or any bike) for grocery hauls or carrying groceries or small people, a trailer is great.
Cheers,
John (outside fontainebleau)