refractor design

How does overall design of an OTA affect performance? Can you have
a top quality ED objective with a medium standard 3 or 4 baffled system and
still
get excellent returns? The light path is what matters. Should it be an
issue if that path
is passing through 3 baffles or 6 assuming that the interior of the OTA is
as black as you can get it?
And what about the focuser barrel? As long as it is of rack and pinion
design.

My point is, can you put a porche engine into a 73 volkswagon and still go
fast?