I recently did a comparison of a bunch of radios on AM/MW.

The Tecsun 550 was really bad on AM/MW (it is good on SW, however).

Here are results, if you would be interested.

http://www.radiointel.com/review-mwolympics.htm

--Russ K3Pi

Also if you go to the review section of radiointel.com - there are
reviews of quite a few radios.