Wanting more drastic alterations to the GUI is going to prove problematic. Even if Virgin hear what you are saying then it would be up to TiVo in the USA to make any amendments and not Virgin Media. This is the problem with out sourcing.
You are more likely to attract the attention of Virgin Media if you post opinions on their own site rather than here:
TiVo - Help & Support Forum
The box is sans a display because of costs. It is cheaper to make without one than includes one. The cisco version of the hardware is derived from a cable STB that did originally have a display.
The outer casing is Virgin's doing and cheap plastic, cheaper than the shiny finish of the standard STBs and Its aesthetics are a matter of opinion, but I see nothing revolutionary or of note in this respect. The case looks as though someone without any product design skills has attempted to meld a PS3 with a SKY HD box? Virgin appear to have tried to continue the design of its superhub on through to the TiVo, but with cheaper materials?
Anyway, this is off topic and a firmware update's primary function is to rectify bugs and glitches apparent in the setup as a whole and not redesign the GUI.