The image on the right is clearly much blurrier, there is a marked loss of detail on markings and small details, and the new compression has visual artifacts.
The worst example I could find was the knee pad marking on The Angels of Redemption.
In other areas, the colour looks grayer or is gone altogether. An example here is the Angels Nepenthe's bionic eye.
Im a graphic artist on a 24" wide-screen monitor with calibrated colours, so the difference may not be as marked for everyone, but to my eyes there is a very clear loss of quality.
Visuals should be visually good, and in a visual presentation, it really shouldn't have to suffer due to other concerns.
Also, I really don't think image weight is that much of an issue anymore, even though there are a lot of images.
If this is a preview only, then ok, no problem, but if it is meant as the final presentation, then Im sorry but the compression ruins the presentation.
It may also be a good idea to use another font. - A sans-serif font would be best. Or at least look at the anti-aliasing method for the font, because the text in both versions is a bit hard to read.
Other than that, great project!
Keep it up!