Slide films show more contrast than print films, thus, I use slide films exclusively for the H-alpha work. Faster films may freeze the atmopheric turbulence, but the price is grain. With the monochromatic subject, grain gets to be extremely noticeable. I use a Meade 2080-LX3.
Prominences can vary gretly in brightness.
Scanning slides do bring out more details than what one may see on the film. I hope this helps some of your other customers. You may post this information on the site if you wish.