There are so many decent products out there on the market
TBH I use mainly AG products but have used others and they are just as good. I really rate megs gold glass shampoo and wouldnt use anything else now!
Having said that I really like AG fast glass and always use that stuff.
My cupboards full of AG stuff, like Simon said its decent when halfords do 3 for 2, even better when they do buy 1 get 1 free