We have 6 10x20 shelter logic frames and always use shelter logic replacement cover!
They are made of a quality material that lasts for 3 years of daily summer use, and we would never
use anything else, we've tried and came back to Shelter Logic.
One year we had a problem with a gromit in a new cover, I contacted them and they replaced the cover right away!
That is service!!!!!!!!!
Pros:Quality material, replacement covers always fit just like the originals
Cons:none that we have ever seen