[astra]

You, guys, know so much about editing/tweaking HTML files.
Sure you can create a perfect file.

I don't know anything about it. All I can do is use a piece of s/w to create ebook.
I can learn how to use the s/w with GUI. It is a different thing from learning a whole new subject of editing HTML files, CSS and understanding how it works.
And if one doesn't know anything about HTML and CSS, is it as easy to create a perfect* epub as it is easy to create LRF in Book Designer?

I think not. I hope I am wrong.

* under perfect I mean, when you upload it to the reader, there are no hiccups at all, no slow down when turning pages, accessing TOC, changing font size, no crashes.