Very nice – glad you got something out of it
The Murata regulators are direct drop-in replacements for the 78xx series regulators.
This means they actually cut off when input is less than 7V, which means 2S operation is right out.
Otherwise, they are nice parts with 1.5A current and up to 36V input (I never go that high) for less than a fiver.
The CUI ones are also intended as replacements, but fully potted, and thus bulkier, and also they don’t come in high current options (typically 500 mA.) They have some higher-current ones, but those are expensive and big. Still potted, though, which I guess is good if you have other bare conductors nearby or put your circuits in harsh environments or such.
The Polulu ones come in much wider range of output voltages, go higher in currents, deal better with lower input voltages, and are all around handier for general purpose DC/DC conversion when I don’t want to make my own board. I guess the Murata and CUI people assume that anyone who needs something more advanced than “I’d like to burn less power with this 7805” will just design it into their own board, because their target is designers who make between hundreds and hundreds of millions of copies …