We recently started using this plugin on our site, e.g. here:
The plugin appears to resize the images correctly, but, two issues:
1. In the Attachment Details pane when you insert the image, under Resizing Information, it always says "This media was not resized by Limit Image Size" even if it was.
2. The attachment is creating very large file sizes. For example, an image from that link that has been resized is now 1448x1086 pixels, and 2.5MB. A picture with that dimensions should be ~300KB, so it's around 10x as large as it should be.
The second one is obviously the bigger issue, since at the moment Limit Image Size isn't helping make the site any faster, which is the entire point of the plugin.
Thanks for developing this, though, It's such a necessary thing for writers that aren't savvy about optimizing file size, I'm kind of surprised that it isn't built into WordPress.