I feel I use more when I buy the cheaper brands, like Extra. But when they are on sale for $2 a bottle for the 40-50 load size, I guess using a bit more is ok.I prefer to use Extra with OxyClean or bleach alternative. I pretreat when I see a stain (with a 2, 6 and 8 year old, most shirts).
I also use Arm & Hammer free and clear/sensitive skin and buy it on sale.
Since DH cannot stand Tide, I've never had it to compare but I know it's the most expensive. I did use Era until middle DS appeared to have a skin sensitivity to it or the scent--not sure which.