I don't have kids, so can't comment on those trailers.

I do have the Nashbar Cargo trailer, the second gen one. So far it's really light and has handled everything I've been able to throw at it! Got it shipped to me for less than $100 too. I'd look elsewhere (Maybe a BOB) if you need to carry more than 45 pounds.

http://www.nashbar.com/bikes/Product..._#ReviewHeader