You think it's bad driving a car as heavy (and long wheelbase) as the Omega - I was driving the MR2 home the night of the heavy snowfall in Feb (I moved house in the heavy snowfall of December
) .. by the time I'd made it from Epsom to Bracknell you could no longer see the road - I got stuck 100yds from my house as I turned a corner from 'slightly driven on' snow to 'virgin snow' and the front end sank in to it like a snowplough
But by heck was it hard getting up the hilly bits to my road; short wheelbase RWD cars like to swap ends fast!
Fortunately two passers by came and dug me out of the drift and we managed to 'dig' the car to my driveway.. where it remained for nearly three weeks before I could get it out again 
That night was bad, day workers left at 5 and came back to work again by 7, slough was totally grid locked, my boss left slough at 4, early enough to gat half way up the m4 and sit for 5 hours in traffic turn round back to slough and get the train to Bracknell.
I thought stuff that and worked two shifts back to back and drove home at 6am in relatively calm conditions. Must have been 50 lorries parked on the m4 and three times that many cars along the back roads, bedlam.
Car was skipping around all over the place though, and the abs is shite in ice and snow.
But these conditions are exceptional in the uk in recent years, as said, if we only get rain this year we will be waisting our time and money surely? Or not?
nope .. winter tires are more grippy and much much better on a rainy wet surface then the summer tires..
(remember their compound are designed to be soft on low temperatures..)
and I can say the same even on dry..
but the drawback is/are
1 - you will consume more fuel
2- your acceleration will get worse..
3- your tire life will shorten..
1 - Potentially, yes. But my experience is you spend more time sitting around going no where in winter conditions so fuel consumption always hurts

2 - How / Why? Assuming the rolling radius is the same, the tyre weights are the same and there's no slip, I can't see why that would be the case.
3 - It's nice to look at the tread life a different way. Unless you're doing epic miles winter tyres will last a good 2-3 seaons, and that's 2 or 3 winters you're not eating your expensive summer tyres or corroding your favourite alloys

This
winter tyre buying guide has led me to really want to try those Contis, I hope we get some snow this year so I can really test them out