I can't speak to that pillow but I have a latex pillow and its cooler than you traditional memory foam pillows. Not sure about the 'cool gel' marked stuff though
I bought a pillow similar to this for around $25 at CostCo B&M a few years ago and I love it:
https://www.costco.com/Comfort-Revo...Memory-Foam-Bed-Pillow.product.100121491.html
It's actually more like this but was considerably cheaper:
http://www.jcpenney.com/sleep-innov...d-standard-pillow/prod.jump?ppId=pp5002970144