Well I'm looking at this part from TI http://focus.ti.com/docs/prod/folder...4lvc4245a.html
This is for data signals, not as a power voltage regulator, so I don't think I'd ever try to use a dc-dc converter.
This chip was designed specifically for what I'm trying to do, which is switch the voltage levels of a data bus. I can't really do this in an opamp, where I have bidirectional signals in some cases.
I know there are some logic gates with almost no propagation delay, but I'm asking if a propagation delay of 5-9ns, which is the case for some of these translators, is going to interfere with a constant stream of data running in the hundreds of MHz.