I like the quality of the bark gathered in autumn better than the one in spring. It seems more soft plastic like to me. Seems more brittle in spring, but a little easier to remove.
Here it is still quite easy to remove, but I have heard from British friends that the bark in Britain is overall more difficult to remove over there and that the season is shorther. Also, our bark, especially from the mountains, is generally thicker.
From what I have heard, the bark is hardly usable many places in Britain. But if you still want to have a go I recommend lots of boiling water and gentle pounding to remove the sheets.
Torjus Gaaren