The TCUSA cover is interlocking double walled aluminum which can hold over 500 pounds. The canister is the smallest of any retractable cover at only 8" x 8". Cover has 4 drain tubes instead of the typical 2.
PE slats are not double walled and are not interlocking and has a significantly larger canister. No more than 200 pounds on the cover is recommended.
TCUSA:
http://img.photobucket.com/albums/v4...aus/TCUSA4.jpg
PE Full Metal:
http://img.photobucket.com/albums/v4...fmjr_cover.jpg
http://img.photobucket.com/albums/v4...r_canister.jpg