For years now I've stuck with Westland feed, weed and moss killer and to be frank it was a poor product, it make the lawn slightly greener in patches, killed parts of the moss off and certain types of weeds.
This evergreen 4 in 1 product however, (first time i have used it) is already an improvement over Westland's version, The WHOLE lawn really does look a darker green, the grass has thickened out, moss has been killed and many weeds have also been killed.
It seems a finer grain to westland's product and there seems to be more blue crystals in it (don't know what they do) but they seem to be working, just apply it 2 days after mowing and water in two days later if no rain has fallen!!!
PROS: very impressed at the speed to which it works, dark green lawn looks nice, more dense grass, moss is dead!!!
CONS: Doesn't go as far as they say even when spreading at the rate they recommend!
VERDICT: Even within a few days you can see the results, which are better than most products on the market, i don't know what the long term effect on the lawn will be but for now it looks impressive, be aware that you will require more than you think to cover your lawn!!