I bought 4 of the small 3A small toroid drivers on purpose from LCK-LED (when they were very cheap).
Does perfect direct drive in a 3 series led 3 series configuration on high. And if you want higher low and medium, just resistor mod it.. I set mine up to do about 5A (on high, but it made the lower modes higher too, which I wanted)
If lightmalls can set them up to have low voltage protection with 3 cells it seems like a great budget choice no matter which version you end up getting. If I got the 3A version when ordering the 5A version I would just ask for a partial refund and get them even cheaper.. ;)
Ill update my Lustefire 3xU2 mod thread about it some day..