I offer diapers with both Bamboo/organic cotton Fleece and Bamboo/organic cotton Velour and often get questions as to which is better. I love them both but both appeal to people for different reasons.
What is bamboo fleece? It is similar to the fabric used to make your favourite sweatshirt. The jersey side is silky soft and the fleecy side is fluffy soft. The fleecy side can get pilly initially, however I like using it both ways and my girls have never expressed a preference either way. The weight I use is extremely absorbent, moreso than the velour, and is slightly bulkier than the velour. Most of my girls' diapers are made with bamboo fleece. Banana Bottoms fitted cloth diapers will not need extra doublers. Of course, there will be the few exceptions to this but I use mine comfortably through naps and night time with no leaks.
What is bamboo velour? Bamboo velour fabric is silky soft and very yummy. As a next-to-babe fabric, the softness can't be beat. (I have a skirt made from this and it is great!) This is very popular with diaper makers and with good reason. It provides a slim layer of absorbency, reducing bulk in a diaper. I don't find it's weight to be as absorbent as the bamboo fleece, so Banana Bottoms diapers are paired with bamboo fleece using velour as the inner layer and topper on the soaker, providing the softness of the velour and the super absorbancy of the fleece.
Either way, you can't go wrong with bamboo fabrics. They are all highly absorbent, extremely soft and silky and perfect for use with cloth diapers.