They would be great for 6mm, if there were suitable figures. A bit easy to get away with proxies/conversions in 6mm than 15mm though. I would use the flyers for 15mm too though.
You've been watching Stroezie's work, right? Already done that.

Strangely, I think the flyers work well for the 28, and would do for large ships in 6, but that tail portion seems big for the inbetween 15mm. Can't explain it, of course.
Doug