I've installed and played with the new version. I like it. One thing that threw me off initially was that it doesn't display the page number it's currently working on, and I thought the program had frozen. Thankfully I browsed through the directories and saw that it was creating images so I left it alone while it did its thing. Perhaps you could add a more obvious indication that it's still working so people know to not force close it. If a page display isn't simple, maybe a percentage done would be better, like:
[55% complete]
or something like that.
Secondly, I tried the split function and I think it does what it's supposed to, but not what I thought it was going to. Sometimes a normal manga will have an image that spans two pages, but the rest of the book is normally page by page. I thought this function might intelligently split files that were much wider (nearly twice the width of a normal image in the collection) into 2 pages.
P.S. Small help tooltips when hovering over different options would add a nice finish to your project
*You still need Imagemagick installed in order to use this software.