I mainly grow turk's cap and various unintended crosses from it, and I find the baby pumpkins taken at any seedless stage (normally between 75mm and 150mm) are delicious cooked like courgettes - in fact they are better than any cooked pumpkin I've ever tasted.
They are so good they are always our first choice for making fritters (served with tzatsiki/raita) - this is the best way to appreciate the extra nutty taste they have.
On the other hand I've tried babies of delicata tribe, crooknecks, crown prince, and every conceivable cross between them. Most aren't as good as turk's cap but I've never found one that wasn't perfectly acceptable as a courgette substitute.
BTW Turk's cap also produce nice fat seeds of a good size - which are the best tasting part of any pumpkin.
I don't grow pumpkins just for fruit size so I have no experience of those kinds.