I'm the biggest Drummond fan you'll find. But Davis is unquestionably the better player right now. If Davis stays healthy, he's on a HOF career path, and will likely be a top 3 player in the league as soon as next season. He's the much better basketball player at this point (though you can certainly make the argument that he's more of a 4 than 5. Davis reminds me of a young Tim Duncan).
That being said, Drummond has better physical tools and has shown the ability to dominate despite still being pretty raw and not getting many touches on offense. Drummond is already arguably the best rebounder in the league, and as he gets older, develops his back-to-the-basket game, and actually gets consistent touches on offense, he can approach 20+ PPG pretty easily to go with his 13+ rebounds. That's rare air in NBA history. People compare Drummond to Dwight Howard, but Drummond is bigger and a better athlete; which is absurd. Drummond reminds me more of a bigger Moses Malone with his superior athletic ability and relentless motor on the offensive glass.
Both are so young and have long, long careers ahead of them. Davis is the better player now, but it will be a lot of fun to watch both players develop.