Money and Decimal are fixed numeric datatypes while Float is an approximate numeric datatype. Results of mathematical operations on floating point numbers can seem unpredictable, especially when rounding is involved. Be sure you understand the significance of the difference before you use Float!

Also, Money doesn't provide any advantages over Decimal. If fractional units up to 5 decimal places are not valid in your currency or database schema, just use Decimal with the appropriate precision and scale.