If I had to buy again I would get a solid floor one from Germany (brand name=Littleman) which folds down very small and converts to pushchair. And you can buy it for about £50 including delivery on Ebay -- which is what my friend did.
I would like to try some cheap trailer like that for a while (Lidl also do them occasionally, Argos one may be similar). If I didn't like it, I would look seriously at the Burleigh Delite OR the Chariot Captain (see www.kinetics.org.uk). These cost around £400. The Captain is a solid floor very good quality trailer for 1 or 2 kids, with lots of cargo space. I saw one in Norwich 4 months ago & was very impressed. There is also the Wike trailer , which is probably as good as the Chariot or Burleigh but about £100 cheaper.
What we have is the Chariot Cougar 2. It's main defect is the hard-to-get-into & limited cargo space.. but it is good quality overall.
We have also had a Koolstop Caboose, and were pretty happy with it, really. But the fabric and hitch both wore out after 2 years use (pretty frequent use, admittedly).
If you import from outside UK make sure Customs identify it as a baby carriage, not sporting equipment (big diff. in import duty or VAT).
You can see more trailer thoughts on my webpage .