We have used both products, and have come to the conclusion that they work, in fact they work better than any other attractant or cover scent in years.
For those of you who have been around a while, years ago Russell Hull once marketed a product called cover up, it was dark green and smelled of vanilla extract. I have used the extract, but the imitation extract, don't use the real thing because it has alcohol in it.
When we can't get the deer dander, or VK, we will use the extract, or no cover at all. The only other scent we use, during the rut, and pre or post is Hawgs Unlimited Buck Fever scents. The best thing going, and it will not go bad from season to season.