Oh yes. There'll be no drastic changes like if you converted with calibre. I didn't mean to imply that. I just didn't know how much of a perfectionist I might be dealing with, so I erred on the side of caution.
Sigil can still be quite sluggish when dealing with very large, single html files (more so in Book View than Code View, but still...), but the more you split it up... the more responsive it becomes. Depending on how huge your file is, it could still be quite painful—and possibly lock up. But I certainly wouldn't be afraid to try it.
