Headlight Lens Repair Questions

My headlight lenses on my wife’s 99 Altima are real dull & cloudy. I thought about replacing them but now I see that there are some restoration kits available. Has anybody tried anything like this? Does it really work? Here’s a couple I was looking at:

http://www.autobodytoolmart.com/3m-headlight-lens-restoration-system-39008-p-16386.aspx

http://www.autobodytoolmart.com/symtech-bright-solutions-headlamp-polishing-car-care-kit-75010010-p-16214.aspx



Thanks