Personal opinion based on having consulted for P&G:
Generally, Tide and most of their other products work better & are better than their competition's. They spend more money on R&D and they care about the quality of their products.
I've been in a lot of their production areas in the US / Canada / Europe / Japan and even Saudi and their quality controls are in the top 2%. South America and Korea and some of the products in 3rd world countries - that's alltogether a different subject.
Other products also work very well.
My advice is to try different products, and if you can't tell the difference, go with the lower priced product.
Regards,