Best, Brightest Barlow

Thanks to everyone who responded! It looks like I'll be picking up a partial set of high performance orthos to squeeze out that last little bit of contrast on DSO's. One more question: has anyone noticed similar effects in barlows? That is, do some barlows have better contrast/brightness due to coatings or design? Seems like it would be a shame to park a bright contrasty ortho on a barlow to get a higher power with good eye relief and then lose the brioghtness/contrast.