We began using the all in one tablets when they became available but are sure that they have decreased in efficacy over the years.
Only last week we bought 'normal' tablets, adding rinse aid and salt and the difference is astounding - for the better!
Previously, our glasses were dull, certainly didn't sparkle, and it was as if there was almost a film over everything. We assumed it was our hard water that was the culprit but now we have sparkling glasses and the dishes actually look clean.
We will look at the Tesco range to see if they sell 'normal' tablets, too as their dish-washing products have been recommended here.