I've played Shadowrun, but that dice pool system never felt right. The FFG Narrative Dice System used in Genesys and the Star Wars RPGs is the only dice pool I really like, although the Wrath and Glory system intrigues me, too. I know D&D DMs are sometimes encouraged to roll a d20 and use the average damage number for minion attacks to streamline the system on their end, and your d20 system sounds a lot like that. "Did you roll in the success range? Here's your result!"