Are these any good?

[Big Dave2]

Nice one, Dave.... very tempted as the satnav looks better than the Vauxhall standard one... does everything work with all the steering wheel controls etc, as they claim?

The steering wheel controls operate the phone, both to answer and reject calls. You need to use the touch screen to call up your list of contacts, although if you press the call button on the wheel twice, it will bring up the last dialled numbers.
You can skip to the next/previous track with the same scroll button that you use for station changes and CD track changes.
To select music though (i.e. MP3 through USB memory stick) you'll need to use the touch screen, unless they've since changed it. You can jump back to the radio or CD with the selector button though.
The Nav is totally controlled via the touch screen.
Volume button works as it always did as that is still controlling the original stereo. The Carvision system is tapped in the Aux socket connection and the jack socket in the cubby hole is made redundant.

Give them a call if you've any questions. I found them really helpful before I committed in parting with my money.