When we're talking about entry-level and mid-level kits, it's all even for me. Sonor and Pearl both make outstanding kits in these categories. It's just a matter of personal preferences.
When it comes to high-end kits... I choose Sonor. Their top-of-the-line drums such as the SQ2, Designer Series, and the DeLite are among the best-sounding, most beautiful, most well-designed, and most well-crafted drums in the world. And some Sonors appreciate in value. However, all that A-1 quality comes with a heavy price tag. Value-wise, Pearl's Reference, Masterworks, and Masters series drums are a better and more practical choice, without compromising quality.
If we're talking about pedals and hardware, I'd go for Pearl. I haven't tried yet the high-end Sonor pedals, but they do look interesting. If top cats like Thomas Lang use them, then it must be good.