Using some of the high street brands doesn't always make the car look better or last longer.
Mer is extremely dusty and the finish is average, and don't be taken in by the fire demo trick....
A/G SRP is a polish and as such will take a thin layer of paint off each time you use it, and after about a week the paint is fading again, I know I used to use it and swear by it. Oh and it's dusty. Expensive ? Yes as you use quite a lot of it.
Using some of the premium brands will make the job quicker, with no dust and you can get the wax on the trim with no aggro, as it's just a wax. The shine you will get is incredible and very deep. Value for money? Well you do pay more for it initially, but it works out at about a ?1 a wax for the car in the end, as the tub of wax will last about 40 waxings.
If you are happy with what you use, fair enough. If you want someting that is easier to use and gives a better result, then give a premium brand a go.
John.