agreed lefty i had the same thought that i want to know what chip is in it ? it almost looks like they are hideing it .. not that im vary good at reading a data sheet and understanding it but i can pick out the real bad points and have an idea of whats there..
It actually says: Efficiency up to 94%, note the up to part. The actually efficiency of any switching regulator will be a function of the input voltage, output voltage adjusted to and the current draw from the load. So its efficiency number is variable within a range. Most switching regulator datasheet will have graphs showing the efficiency Vs various operation conditions. But in all cases they all run much for efficient then linear regulators.
im just guessing from what you said there .. but say the lower the input voltage is for a switching regulator say its good for the 4 to 48v in put but it s out put is 3 to 20v ... it would be more effciant to keep the in put on the lower side close to what you out put is to keep the heat and waste down ? so i would be useing the full 3 to 14v often so my in put should be 16v and that would be better then puting a full 20 to 32 in amppers aside.. i know ohms law will afect this but just for example is that what your saying from you quote above ?