My daughter was exclusively on B.M for the first three months and we started to wean her to formula.  She received half B.M and half formula for until she was 5 months.  She liked the taste of the member's mark formula better than the B.M.! 

We are extremely happy with it and have found it mixes well with a formula pitcher.  Also, the price (about $20 for 3.5 pounds) can't be beat!