Alloy wheels are not much lighter in weight than steel wheels, and can be a pain in the bum. They look stupid on certain cars like Rolls Royce and Bentley, like a fairground amusement, who wants to look at rusty old brake calipers through the spokes, and wheel nuts can come loose too. As far as spare wheels and punctures are concerned I recomend an aerosol of Latex to fix ordinary punctures on the tread area or leaks around the rim and tyre bead. They do work well if the instructions are followed. No good for tyre wall punctures because of the flexing. Holts ones are the best. I've used em about 3 times and they've worked well. Be careful with the low profile bloomin tyers going over potholes the wheel rims can chop the tyre wall and destroy it. Alloy wheels, low profile tyres and power steering are the best things that ever happened to the tyre trade.