First, I'd like to say that I am cautiously optimistic about the changes in S5.
If you were accustomed to working in Pixel Editor, the update brings everything into one program. No need to jump back and forth between programs (other than SS).
Some issues were fixed also, with big improvements in usability of the preview layout tools. (i.e. resizing imported props, better functionality of groups).
With the integration of a visualizer window directly in the Sequence Editor, I don't see a huge need for a separate visualizer program.
However, by removing the visualizer, LOR has removed one of the best features of the suite... the ability to easily create custom props.
That was the biggest strength within the visualizer program.... the tools for creating custom pixel props.
The custom prop tool within the SE (excel-style cell based) is not nearly as good.
I would like to see the prop creation functionality in the visualizer tool returned.
Separately, I would like to see the ability for playback to be editable so that you can preview just the props listed in the current "view"
That way you can focus in on just the props and/or groups that you are sequencing. Why burden the system with playback of all props at the same time if not necessary.
*this only applies to large shows with lots of props.