Delta's can, if not set-up great be a pain in the rear. Leveling in particular. As for a duct upgrade, ideally it would need to be printed in a filament that can handle the heat of being near the hot end, so ABS but that in itself is a pain to print and it smells horrible.
Every printer I have looked at seems to have issues with leveling or warped beds and the level slipping over time hopefully if i can get the level setup correctly with a delta i shouldnt have to do it as often. The QQ S pro comes with a leveling sensor which appears to be fairly user friendly, They use to use a conductive pad but they moved away from that to a mico switch adapter that fits over the hot end. I plan to use PLA at first as so many people have said PLA is the easiest for a newbie to start off with and then once thats dialed in reliably then consider moving on other materials.