I drove a 2009 model over a year ago and was not impressed, I have since read that the more recent models had been improved so I thought I would give another one a try.
I test drove and late 2010 model SRi Nav 160 BHP Diesel.
I loved the interior and the seats, much nicer place to be than the Vectra, I feel the driving the position in the Insignia puts me in the car whereas the Vectra seat even in its lowest position I feel on the car. The Insignia steers better and I just feel very comfortable and at home in it. So for sitting in I think the Insignia is miles ahead of the Vectra and the Interior alone makes me want one. I think the Insignia on the outside looks great too.
As for driving I found it to be no quieter on the road than my Vectra, if it is then only by very small amount, I was hoping it would be much quieter. A bigger problem is how hard it rides, on the Sri 18" wheels that is, it is almost as harsh as my lowered Vectra. I was hoping for a softer quieter ride, in fact I found the ride so poor I could not make a deal to buy the Insignia. I am disappointed as I love the interior of the Insignia but cannot get past the poor ride and high amount of road noise.
So think I will have to stick to my Vectra, unless I could get an SRi Nav without sports suspension and I am not about to buy a new car to modify the suspension. A shame as there are very few other cars I like out there and even fewer where I feel I sit in the car instead of on the car. The other trims are no good as I want the SRi seats and also hate the plastic wood in the SE and Elite versions. I cannot imagine how bad an SRi Insignia would feel on 20" wheels.