Pros: Inexpensive, good fit, long lasting.
Cons: Looks inexpensive, few choices.
Update: My original econobum covers are still going strong! I loved them so much I bought more too. They are being used on my twin toddlers and twin infants. All of my children have different body shapes and I'm impressed with the fit I get on all of them.
My little girl is long and thin, only 11 lbs. and I get a great fit on her over a fitted diaper or sized prefold. The included prefold would still be a bit bulky for her. My 5 month old son is almost 15 lbs. and a very wide baby, he is plenty big enough to use the include prefold with.
With my toddlers we use the covers at bedtime over a disposable diaper to discourage them from taking them off. One of the toddlers is average size and the other is a bit petite. Both fit in the econobum fine at 22 months, the included prefold is not quite absorbent enough for long periods of time but is fine around the house.
They have been used heavily and are amazing me with their durability, especially given the price.
People say you get what you pay for, but the econobum one-size does better than that. It is very inexpensive, ten dollars won't usually pay for a sized cover let alone a one-size cover with snaps and an included organic prefold. AIO or pocket diapers can cost twice this. The econobum one-size is made by cotton babies, the same company that makes bumgenius products. It was introduced as a low cost diapering option but in keeping to their high standards it is still a quality product.
In order to do make this so cheap, they had to make some compromises. Few options are available, initially the econobum was only available in white, it is now also available with green, blue, or pink trim. It is only available in snaps, but that is my preference anyway. The PUL cover doesn't seem very thick, but as a result is slim fitting. It is a very basic system consisting of a one-size snap cover with a snap down adjustment for size and a one-size prefold that is folded differently depending on size. I consider this system to be very user friendly-The one-size prefold is 100% cotton which is hassle free to wash, the snaps eliminate annoying Velcro chains. The prefold is also designed to be used tri-folded which eliminates the need for pins.
While this is a "One-size" system the fit on a newborn with the included prefold would be very bulky. A smaller prefold purchased separately would remedy this and I have no complaints on the fit for older children. I have used these heavily and they are holding up very well. I hadn't expected much for ten dollars but have been pleasantly surprised by this quality product.
Bottom line- this was an excellent addition to my diaper stash. If you are considering cloth diapering, spend the ten dollars to try an econobum. It is an excellent low cost option for reusable diapering.