Radiator reflectors, do they work?

[TSS]

Has anybody had experience of using radiator reflectors (e.g. http://www.shopeco.co.uk/index.asp?function=DISPLA... ) to reduce heat loss from radiators on outside walls and could you feel any difference?

Thanks,

TSS

[TSS]

Thanks for the replies everybody - quite mixed reports. I think I might get some reflectors for one radiator and then do some experimenting with an infra red thermometer.