Long Tubes vs. Shorties (Headers)
There is middle ground here. I use a full long tube but I use Headman graduated headers or 'step-tuned' headers where they modify (reduce) the header tube in diameter on its way to the collector. It is supposed to be a balance between them both.
The biggest difference I have found is in the PITA factor. A 289 in a classic coupe requires that you raise the engine slightly to install, remove driver's side header to drop the tranmission, etc.....shorties are a little easier to manage.
Looks: I think thermally coated long tubes look outstanding under the hood, under the car, etc.
-Q