It looks really cool but there are several aspects where that design overall is placing "looking cool" as a higher priority than usability.

For MoI the main emphasis throughout the product is on practical matters and ease of use first and looking cool is a much lower priority.

A couple of problematic things that stand out is the redesigned program icon is hard for me to clearly identify at small sizes, the current icon is legible even down to a 16x16 pixel favicon.

The very dark viewport background would make it difficult to work with black 2D wire drawings because of a lack of contrast.

Several screens show command UI being displayed inside the viewport area. It's better to avoid doing that when possible because it makes the UI get in the way of the objects you are trying to work on. That's why it is a focus in the real UI to have command options displayed in a dedicated area of the side pane instead of in the middle of the viewport area.

Probably the best part of the redesign is that the icons are looking really good there.

I think mostly the gripes about the Moi UI looking "dated" come down to just the icons not being all done in the modern sparse monochrome style. Maybe at some point I'll be able to give that a little energy but since it's very much just a cosmetic issue it is a low priority.

- Michael