Since we had the babies, we've used 4 brands of diapers: Pampers, Huggies, Costco and a white label brand. If I had to rank them in order of effectiveness, Pampers comes first. Costco is second followed by the white label diaper. Huggies are the absolute worst. Now I haven't tried Luvs but it'll have to really suck to be worse than Huggies. Fortunately, all the huggies diapers we've used were received as gifts. The rate of failure of the adhesive (in the size 1 version) was higher than that of the white label brand. The absorbency of the diaper itself left much to be desired. I'll say about 75% of the time the baby's butt was wet (which means the pee was not being absorbed completely by the diaper). So regardless of price and value, I will not be buying huggies. Each time we receive huggies as a gift, I am tempted to throw them out. That's how bad our experience with huggies has been.
The babies were started on Pampers Swaddlers from the hospital. And I have to confess they are the very best in disposable diapers. The material is very very soft and the absorbent crystals work exceedingly well. The diapers absorb so well that sometimes it's hard to tell whether or not the diaper is wet. The rate of failure of the adhesive is 0% (works all the time) and some of the diapers even have an indicator strip that tells you when the baby is wet. Sounds like a minor deal but it helps eliminate one potential cause when a baby is wailing.
In terms of price, Pampers was the most expensive. However it wasn't that much more expensive than the Costco brand. The difference was about 6 cents. That doesn't sound like a lot but when you calculate how many diapers a baby goes through in a single day, that 6 cents difference adds up to $175 per baby (8 diapers a day * 365 days). Multiple that by 2 (twins) and that's $350 each year!
The white label brand was by far the cheapest but it left a lot to be desired in terms of softness and fit.