Well, I got fed up with having to borrow the "Golden Laptop" from work every time I need to use my cheapo Tech 2 (quite often with a 3.2!) so I thought I'd investigate another possibility.
Got myself one of these, which arrived today:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=250208955409What turned up was actually slightly different to the picture, and had a USB rather than serial interface but it's a very nicely made unit. For the price, I'm impressed.
The first thing to say is that these only work on OBDII vehicles, so 2.2/2.6/3.2. However, they aren't specific to Vauxhall and should work with most OBDII and CAN vehicles. Without paying for more software they will only read the engine ECU too. However, since that is what normally gives grief I decided it would be useful.
Got it out of the box, installed the software on a laptop and set out to discover the reason for my emissions light being on (as if I didn't know!). It worked absolutely first time, reported things in english and is clearly much more stable and less fussy than a cheapo tech 2. P0420 and P0430 were showing (usual cat efficiency problem on a 3.2). The codes could be cleared no problem.
The supplied free software (scantool.net)
http://www.scantool.net/ can do basic code reading and clearing from the engine ECU and also reports live data including all main parameters likely to be of interest.
I will probably investigate a few more software packages available in due course but, in my opinion, this is a good alternative to a cheapo Tech 2 for anyone who has a later Omega, for similar money. It took a lot less messing about to get it working!
Kevin