Perhaps it's the noise that gives it the name - it came over my gaff on its way to Fairford after validating at Farnborough on Friday pm, and when I heard it approaching I had to go outside to look, as it just sounded "different" to anything else - more jet roar than turboprop drone, but definately a bit of both - something like a roar/growl??
And it was nipping along too - I get a lot of Q400's in the overhead here (Flybe's in and out of Southampton) and it looked noticeably quicker than those.