I think Vauxhall hit the styling right on the head with this one. I really like the exterior - hints of lots of bits of cars I like. Much better than the bulbous Insignia. Inside also looks stylish, but having spent some time in the Insignia I'm pretty sure it'll be frustratingly complicated. Too many buttons doing too many things. For air-con/climate control you only need to look as far as the current civic to realise how everything can be done clearly, taking up little space and for the greatest ease of use (although one rotary controlis hidden slightly behind the steering wheel...). (it didn't let me write the word describing an object you'd find on a cupboard door - hence "rotary control!)
On a technical note does the I30 not just have a "posh" torsion beam set-up - that is only being independent by virtue of trailing rear arms, as opposed to the "true" multi-link set ups in the Golf and Focus (I know Ford refer to the Focus as the "control blade")? Or am I wrong...?
Gear ratios are rarely chosen now for how the car feels on the road, merely to creep under the nearest CO2 band. It's frustrating - I've always thought 6 speeds was perfect with the first 5 "close ratio" to provide decent acceleration and the 6th purely for cruising at 60mph upwards.
All in all... I can't see many people choosing this over the Golf if they had the choice. I'd take the Golf and I don't even particularly like VW!
On a side note - you mentioned the Mondeo and Passat were "softer rivals" - is that an admission that the Mondeo reviews early on did not fully represent the abilities of that car? Ownership wise I've heard some nightmares, though enjoyed the couple of times I drove it. The Passat is also a very sound car now, partly the introduction of the TSI engines, but also the introduction of CR diesels.