I find it fascinating how the electronic flash market has evolved.
TTl flash is usually bundled with a bunch of connectivity features. The TTl part has some advantages, particularly where you are doing close focus work, but in most cases it is the connectivity features (automatic aperture matching, synch speed control, focus linking and multi flash coordination) that sell the flashes.
The auto-exposure function built into most modern flashes does a really good job adjusting the light output of the flash. And learning how to use it properly is pretty simple.
In a studio setting, most of the connectivity functions aren't that important. And in the case of a Hasselblad 500ELX aren't even available.
I use a Metz 60CT2 which operates in TTl mode with some of my cameras. It is a great (and large!) flash, and I am sure the 60CT4 is too. But I don't always use my 60CT2 in TTl mode with those cameras, because it works well in auto and manual mode too.