Is kilz better than zinsser?

Both Kilz and Zinsser offer effective primers. For mold and mildew, Zinsser B-I-N Shellac-Base Primer and Zinsser Perma-White Mold & Mildew-Proof Paint are highly regarded for their excellent sealing and stain-blocking properties. Kilz primers are also effective, but Zinsser often gets the edge for severe mold and stain issues.