While I've never been motivated to enter the SPSP comp, I don't see a problem with their rules. To get an extraordinary image does take some effort, and, for deeps sky at least, some seriously long exposures.
They have lots of different categories, so, again there many many types of images that can do well.
The Malin Awards are are quite different. While technical aspects of an image do count (particularly the colour !
) they don't count that much.... Terry Cuttle's overall winning image had all the *right* elements: great technique, beautiful subject matter (McNaught) which was also framed superbly.
The fact that Terry chose to haul his rig up to the Glass-House mountains to get all those elements in made him a deserving winner.
Despite the heavy artillery in my backyard, the images I actually did well with were taken with very modest gear. Such is the nature of the DM awards which I suspect reward something fresh/different or a novel approach.
That's pretty hard to do with the vanilla/bright deep sky subjects: M42/M8/M17/M16/47 Tuc/Omega etc. have all been done to death...so choosing them as you subject you'd want to also do something out of the ordinary with them.
Just my two cents worth....
Peter