I have test driven both cars now, both were also saloons.
Very quick car, but as mentioned already, a little bit of 'nothingness' below 3700rpm as the turbo spools up, but after this point it's as quick as hell. Under 3700rpm, it feels like it is being held back and your going through the revs just for the sake of it. This feeling of nothingness is not exactly true though as the speedo is still moving towards the illegal speed limit very quickly. I would just liked to have had a little bit more in your back grunt from low revs.
I reckon this is purely down to the mapping as Opels policy is to have cars now that don't feel turbocharged but very smooth, this is the Insignia's downfall, it's too smooth. But it's alot easier to drive around normally than the Vectra VXR and you can potter about and not get tired of aggressive throttle responce etc.
Equipment levels are second to none, with only 20" wheels, leather and Sat Nav being the main options you would want. The seats are amazing and very easy to get comfortable in and really hold you in place. The steering wheel is a little on the big side and I am not really a fan of the silver trim on the steering wheel that replicates the vents on the bumper. Build quality is way ahead of Vectra in all area's
The handling is very good and traction levels excellent, but still feels in alot of ways like a front wheel drive car.
Until...............................you hit the VXR button, this sends 80% of the drive to the rear wheels at all times, and on the bendy stuff, you can then really feel the back dig in when exiting corners. It sort of gives you the best of both worlds, the instruments changing from white to red is a bit of a gimmick, but I have to say I like it alot! Steering could be a little more weighted and feeld a little light, even on VXR mode.
I think that Vauxhall should have altered the mapping when on 'VXR' button to not only stiffen up the shocks and throttle response and also the power to the 4x4 system, but make the acceleration feel quicker, then in normal mode everything calms down. The 'Sport Button' is a bit pointless when you have normal and VXR mode.
Like the BMW M5, it has 400bhp, then when you press the 'M' button you get the full 500. I think Vauxhall should give the car 300bhp in normal mode and say 350/360bhp in 'VXR' mode.
For a start, the S4 is alot smaller than the Insignia when parked side by side.
The enigne is superb, the 3.0 V6 sounds very much like the Insignia but as it's supercharged, you get instant punch and it feels more like a V8 than a V6, this instand punch I think is what gives the car it's slightly better 0-60 time over the Insignia VXR. But once on the move, there is nothing in it with the Insignia maybe having the edge.
The steering is alot sharper on the Audi and you feel more in touch with whats going on with the road and you tend to feel more of whats going on with each wheel. Supercharger noise is almost silent which is a shame.
The handling is sublime for this size car and the quattro 4x4 system is very good, although both the Insignia and S4 both use the Haldex system, the Audi seems to have better overal grip. If if we were at somewhere like Bruntingthorpe with both cars, I think the Audi would struggle to lose the Insignia.
The interior is very good I must say, better than the Insignia? In certain areas yes, the piano black trim on the Insignia lets it down as it's a little plasticy but it's not far behind the Audi at all.
I didn't bother with mpg tests as both car were pretty new and I know both won't be brilliant.
In my opinion, the S4 is the more polished article, but this is Audi's 3rd generation S4 so they have had some practice, where as the Insignia is Vauxhall first attempt at a hot 4x4 saloon car.
The VXR feels like it has soul, where the Audi just doesn't. In some ways it is too perfect.
Looking at both as standard packages, £31k for a basic Insignia VXR compared to £36k for the basic S4, is the S4 good enough to spend the extra £5000 on?
err...............................No. The S4 is good without a doubt, no it's very very good, but when you consider the standard spec of the Insignia VXR and it's very few short falls compared to the S4 I would be hard pushed to go for the S4.
OK, the VXR is an expensive Vauxhall, but it's overall running costs, servicing etc is considerably more on the S4 than the VXR.
The VXR is not cheap at £31k, but when you consider an Insignia SRi 2.0 CDTi 160with as near same spec as the VXR is £29000, it makes the VXR seem like excellent value for money.