ECS keeps listing these Heaven & Earth designs as over 2 threads on 25-ct linen. As you can see, this makes the picture awfully big - 3" by 4" 2'. H&E recommends the 25-ct fabric over 1 thread of fabric, making the design only half as large.
I personally recommend Aida cloth for these "every square stitched" pieces. 18-ct Aida, if you can. It can take the floss weight better.
You don't lose the detail on these big ones; you just have to stand further away. Also, think of the floss you need!